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• Does RVM "failover" to another ruby instance on error?

  - by JohnMetta

  Have a strange problem in that I have a Rake task that seems to be using multiple versions of Ruby. When one fails, it seems to try another one. Details MacBook running 10.6.5 rvm 1.1.0 Rubies: 1.8.7-p302, ree-1.8.7-2010.02, ruby-1.9.2-p0 Rake 0.8.7 Gem 1.3.7 Veewee (provisioning Virtual Machines using Opcode.com, Vagrant and Chef) I'm not entirely sure the specific details of the error matter, but since it might be an issue with Veewee itself. So, what I'm trying to do is build a new box base on a veewee definition. The command fails with an error about a missing method- but what's interesting is how it fails. Errors I managed to figure out that if I only have one Ruby installed with RVM, it just fails. If I have more than one Ruby install, it fails at the same place, but execution seems to continue in another interpreter. Here are two different clipped console outputs. I've clipped them for size. The full outputs of each error are available as a gist. One Ruby version installed Here is the command run when I only have a single version of Ruby (1.8.7) available in RVM boudica:veewee john$ rvm rake build['mettabox'] --trace rvm 1.1.0 by Wayne E. Seguin ([email protected]) [http://rvm.beginrescueend.com/] (in /Users/john/Work/veewee) ** Invoke build (first_time) ** Execute build … creating new harddrive rake aborted! undefined method `max_vdi_size' for #<VirtualBox::SystemProperties:0x102d6af80> /Users/john/.rvm/gems/ruby-1.8.7-p302/gems/virtualbox-0.8.3/lib/virtualbox/abstract_model/dirty.rb:172:in `method_missing' <------ stacktraces cut ----------> /Users/john/.rvm/gems/ruby-1.8.7-p302/gems/rake-0.8.7/bin/rake:31 /Users/john/.rvm/gems/ruby-1.8.7-p302@global/bin/rake:19:in `load' /Users/john/.rvm/gems/ruby-1.8.7-p302@global/bin/rake:19 Multiple Ruby Versions Here is the same command run with three versions of Ruby available in RVM. Prior to doing this, I used "rvm use 1.8.7." Again, I don't know how important the details of the specific errors are- what's interesting to me is that there are three separate errors- each with it's own stacktrace- and each in a different Ruby interpreter. Look at the bottom of each stacktrace and you'll see that they are all sourced from different interpreter locations- First ree-1.8.7, then ruby-1.8.7, then ruby-1.9.2: boudica:veewee john$ rvm rake build['mettabox'] --trace rvm 1.1.0 by Wayne E. Seguin ([email protected]) [http://rvm.beginrescueend.com/] (in /Users/john/Work/veewee) ** Invoke build (first_time) ** Execute build … creating new harddrive rake aborted! undefined method `max_vdi_size' for #<VirtualBox::SystemProperties:0x1059dd608> /Users/john/.rvm/gems/ree-1.8.7-2010.02/gems/virtualbox-0.8.3/lib/virtualbox/abstract_model/dirty.rb:172:in `method_missing' … /Users/john/.rvm/gems/ree-1.8.7-2010.02/gems/rake-0.8.7/bin/rake:31 /Users/john/.rvm/gems/ree-1.8.7-2010.02@global/bin/rake:19:in `load' /Users/john/.rvm/gems/ree-1.8.7-2010.02@global/bin/rake:19 (in /Users/john/Work/veewee) ** Invoke build (first_time) ** Execute build isofile ubuntu-10.04.1-server-amd64.iso is available ["a1b857f92eecaf9f0a31ecfc39dee906", "30b5c6fdddbfe7b397fe506400be698d"] [] Last good state: -1 Current step: 0 last good state -1 destroying machine+disks (re-)executing step 0-initial-a1b857f92eecaf9f0a31ecfc39dee906 VBoxManage: error: Machine settings file '/Users/john/VirtualBox VMs/mettabox/mettabox.vbox' already exists VBoxManage: error: Details: code VBOX_E_FILE_ERROR (0x80bb0004), component Machine, interface IMachine, callee nsISupports Context: "CreateMachine(bstrSettingsFile.raw(), name.raw(), osTypeId.raw(), Guid(id).toUtf16().raw(), FALSE , machine.asOutParam())" at line 247 of file VBoxManageMisc.cpp rake aborted! undefined method `memory_size=' for nil:NilClass /Users/john/Work/veewee/lib/veewee/session.rb:303:in `create_vm' /Users/john/Work/veewee/lib/veewee/session.rb:166:in `build' /Users/john/Work/veewee/lib/veewee/session.rb:560:in `transaction' /Users/john/Work/veewee/lib/veewee/session.rb:163:in `build' /Users/john/Work/veewee/Rakefile:87 /Users/john/.rvm/gems/ruby-1.8.7-p302/gems/rake-0.8.7/lib/rake.rb:636:in `call' /Users/john/.rvm/gems/ruby-1.8.7-p302/gems/rake-0.8.7/lib/rake.rb:636:in `execute' /Users/john/.rvm/gems/ruby-1.8.7-p302/gems/rake-0.8.7/lib/rake.rb:631:in `each' … /Users/john/.rvm/gems/ruby-1.8.7-p302/gems/rake-0.8.7/bin/rake:31 /Users/john/.rvm/gems/ruby-1.8.7-p302@global/bin/rake:19:in `load' /Users/john/.rvm/gems/ruby-1.8.7-p302@global/bin/rake:19 (in /Users/john/Work/veewee) ** Invoke build (first_time) ** Execute build isofile ubuntu-10.04.1-server-amd64.iso is available ["a9c4ab3257e1da3479c984eae9905c2a", "30b5c6fdddbfe7b397fe506400be698d"] [] Last good state: -1 Current step: 0 last good state -1 (re-)executing step 0-initial-a9c4ab3257e1da3479c984eae9905c2a VBoxManage: error: Machine settings file '/Users/john/VirtualBox VMs/mettabox/mettabox.vbox' already exists VBoxManage: error: Details: code VBOX_E_FILE_ERROR (0x80bb0004), component Machine, interface IMachine, callee nsISupports Context: "CreateMachine(bstrSettingsFile.raw(), name.raw(), osTypeId.raw(), Guid(id).toUtf16().raw(), FALSE , machine.asOutParam())" at line 247 of file VBoxManageMisc.cpp rake aborted! undefined method `memory_size=' for nil:NilClass /Users/john/Work/veewee/lib/veewee/session.rb:303:in `create_vm' /Users/john/Work/veewee/lib/veewee/session.rb:166:in `block in build' /Users/john/Work/veewee/lib/veewee/session.rb:560:in `transaction' /Users/john/Work/veewee/lib/veewee/session.rb:163:in `build' /Users/john/Work/veewee/Rakefile:87:in `block in <top (required)>' /Users/john/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rake.rb:634:in `call' /Users/john/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rake.rb:634:in `block in execute' … /Users/john/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rake.rb:2013:in `top_level' /Users/john/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rake.rb:1992:in `run' /Users/john/.rvm/rubies/ruby-1.9.2-p0/bin/rake:35:in `<main>' It isn't until we reach the last installed version of Ruby that execution halts. Discussion Does anyone have any idea what's going on here? Has anyone seen this "failover"-like behavior before? It seems strange to me that the first exception would not halt execution as it did with one interpreter, but I wonder if there are things happening when RVM is installed that we Ruby developers are not considering.

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• HttpWebRequest is extremely slow!

  - by Earlz

  Hello, I am using an open source library to connect to my webserver. I was concerned that the webserver was going extremely slow and then I tried doing a simple test in Ruby and I got these results Ruby program: 2.11seconds for 100 HTTP GETs C# library: 20.81seconds for 100 HTTP GETs I have profiled and found the problem to be this function: private HttpWebResponse GetRawResponse(HttpWebRequest request) { HttpWebResponse raw = null; try { raw = (HttpWebResponse)request.GetResponse(); //This line! } catch (WebException ex) { if (ex.Response is HttpWebResponse) { raw = ex.Response as HttpWebResponse; } } return raw; } The marked line is takes over 1 second to complete by itself while the ruby program making 1 request takes .3 seconds. I am also doing all of these tests on 127.0.0.1, so network bandwidth is not an issue. What could be causing this huge slow down?

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• Best way for programmers to edit XAML

  - by JessicaB

  I was wondering how programmers chose to edit XAML. Most of the programmers I speak to seem to edit the raw XML, but that seems nuts to me since it is such a natural thing for a more visual editor (of course you often have to get down to the raw code ultimately, but isn't there a better way to lay out a grid, or edit a template, or add non c# triggers or manage commands? The one that really set me off was editing a menu -- Visual Studio 1.0 had a better menu editor for C++ than the raw XAML editing experience.) When I edit .aspx files I use a visual editor much of the time, and then for the raw stuff I get into the html code. I am aware of Expression Blend, but that seems far more focused on artistic types and GUI experts rather than programmers. Does anyone have recommendations for a better editor for XAML than VS? Especially so since VS seems to have real nasty problems with XAML editing too, like bugginess and poor performance? Appreciate your helping this XAML newbie.

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• how can I convert String to SecretKey

  - by Alaa

  I want to convert String to secretKey public void generateCode(String keyStr){ KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128); // 192 and 256 bits may not be available // Generate the secret key specs. secretKey skey=keyStr; //How can I make the casting here //SecretKey skey = kgen.generateKey(); byte[] raw = skey.getEncoded(); } I try to use BASE64Decoder instead of secretKey, but I face a porblem which is I cannot specify key length. EDIT: I want to call this function from another place static public String encrypt(String message , String key , int keyLength) throws Exception { // Get the KeyGenerator KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(keyLength); // 192 and 256 bits may not be available // Generate the secret key specs. //decode the BASE64 coded message SecretKey skey = key; //here is the error raw = skey.getEncoded(); SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); // Instantiate the cipher Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); System.out.println("msg is" + message + "\n raw is" + raw); byte[] encrypted = cipher.doFinal(message.getBytes()); String cryptedValue = new String(encrypted); System.out.println("encrypted string: " + cryptedValue); return cryptedValue; } Any one can help, i'll be very thankful.

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• Parsing back to 'messy' API strcuture

  - by Eric Fail

  I'm fetching data from an online database (REDcap) via API and the data gets delivered in as comma separated string like this, RAW.API <- structure("id,event_arm,name,dob,pushed_text,pushed_calc,complete\n\"01\",\"event_1_arm_1\",\"John\",\"1979-05-01\",\"\",\"\",2\n\"01\",\"event_2_arm_1\",\"John\",\"2012-09-02\",\"abc\",\"123\",1\n\"01\",\"event_3_arm_1\",\"John\",\"2012-09-10\",\"\",\"\",2\n\"02\",\"event_1_arm_1\",\"Mary\",\"1951-09-10\",\"def\",\"456\",2\n\"02\",\"event_2_arm_1\",\"Mary\",\"1978-09-12\",\"\",\"\",2\n", "`Content-Type`" = structure(c("text/html", "utf-8"), .Names = c("", "charset"))) I have this script that nicely parses it into a data frame, (df <- read.table(file = textConnection(RAW.API), header = TRUE, sep = ",", na.strings = "", stringsAsFactors = FALSE)) id event_arm name dob pushed_text pushed_calc complete 1 1 event_1_arm_1 John 1979-05-01 <NA> NA 2 2 1 event_2_arm_1 John 2012-09-02 abc 123 1 3 1 event_3_arm_1 John 2012-09-10 <NA> NA 2 4 2 event_1_arm_1 Mary 1951-09-10 def 456 2 5 2 event_2_arm_1 Mary 1978-09-12 <NA> NA 2 I then do some calculations and write them to pushed_text and pushed_calc whereafter I need to format the data back to the messy comma separated structure it came in. I imagine something like this, API.back <- `some magic command`(df, ...) identical(RAW.API, API.back) [1] TRUE Some command that can format my data from the data frame I made, df, back to the structure that the raw API-object came in, RAW.API. Any help would be very appreciated.

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• HOWTO: Deserialize WCF message using OperationContract

  - by Stefan

  Hi, I succeeded in building a WCF client generated by svcutil.exe from the WSDL. Using the generated client proxy class I can call the web service of an external service supplier. I also succeeded in coding a message inspector, as I need to log both raw XML request and response as full SOAP message to the database. For an emergency szenario I also need to be able to "import" a raw XML response. I found many hints on using XMLSerializer or deserializing WCF messages based on the message contract. But how can I deserialize a raw XML response based on an operation contract? For a first test I use one of the logged raw responses, save it to a file and now try to deserialize it to the response type as generated in the client proxy. Somehow I must succeed in calling DeserializeReply() from class ClientOperation. But how to get there? I happily acced any help as I'm quite new to WCF... TIA, Stefan

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• How to color HTML elements based on a user command string

  - by Anonymous the Great

  When you type something like "red:Hi:" it will type "Hi" in red. The following script does not work and I do not know why, (The one who made the sorting PHP function is Graphain, thanks again!) <?php function getit($raw) { # If the value was posted $raw = isset($raw) ? $raw : ""; # Split it based on ':' $parsed = explode(':', $raw); $colorClass = ""; $text = ""; if (count($parsed) >= 2) { $colorClass = $parsed[0]; $text = $parsed[1]; $text = "~~~" . $text . "~~~" . $colorClass; return $text; } } ?> <script type="text/javascript"> function postit() { var preview = document.getElementById("preview").value; var submit = document.getElementById("post").value; var text = <?php getit(submit); ?> var t = text[0]; preview = t; } </script> <textarea id="preview" cols=70 rows=5 readonly>Preview box</textarea> <p> <textarea id="post" cols=70 rows=5/>Submit box</textarea> <p> <input type="button" onclick="postit();" value="Submit"/>

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• confused of $this in cakePHP

  - by kwokwai

  Hi all, I got a few lines of codes in a Model in cakePHP 1.26: function beforeSave() { $this->data['User']['pswd'] = md5($raw['User']['pswd']); return true; } // this beforeSave() works The code above has been tested and it is working in my database. Yet, I am not sure if I can understand it well, so, I re-wrote the code in other way, and it just failed to work then. function beforeSave() { $raw=$this->data; $raw['User']['pswd'] = md5($raw['User']['pswd']); return true; } // this beforeSave() failed to work Why the second method can not work?

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• Interrupt ?13 (ah=48) - don't working

  - by GLeBaTi

  mov dl,00h mov ah,08h int 13h this is code showing normal parameters of floppy disk. mov dl,80h mov ah,08h int 13h this is code, showing not valid parameters of hard disk(may be, my hard disk space is big (LBA)), And I've written this code: mov dl,80h mov ah,48h int 13h it is code doing cf = 1(error). How fix it? I want learn parameters of my hard disk. (http://lrs.uni-passau.de/support/doc/interrupt-57/RB-0677.HTM)

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• Critique my heap debugger

  - by FredOverflow

  I wrote the following heap debugger in order to demonstrate memory leaks, double deletes and wrong forms of deletes (i.e. trying to delete an array with delete p instead of delete[] p) to beginning programmers. I would love to get some feedback on that from strong C++ programmers because I have never done this before and I'm sure I've done some stupid mistakes. Thanks! #include <cstdlib> #include <iostream> #include <new> namespace { const int ALIGNMENT = 16; const char* const ERR = "*** ERROR: "; int counter = 0; struct heap_debugger { heap_debugger() { std::cerr << "*** heap debugger started\n"; } ~heap_debugger() { std::cerr << "*** heap debugger shutting down\n"; if (counter > 0) { std::cerr << ERR << "failed to release memory " << counter << " times\n"; } else if (counter < 0) { std::cerr << ERR << (-counter) << " double deletes detected\n"; } } } instance; void* allocate(size_t size, const char* kind_of_memory, size_t token) throw (std::bad_alloc) { void* raw = malloc(size + ALIGNMENT); if (raw == 0) throw std::bad_alloc(); *static_cast<size_t*>(raw) = token; void* payload = static_cast<char*>(raw) + ALIGNMENT; ++counter; std::cerr << "*** allocated " << kind_of_memory << " at " << payload << " (" << size << " bytes)\n"; return payload; } void release(void* payload, const char* kind_of_memory, size_t correct_token, size_t wrong_token) throw () { if (payload == 0) return; std::cerr << "*** releasing " << kind_of_memory << " at " << payload << '\n'; --counter; void* raw = static_cast<char*>(payload) - ALIGNMENT; size_t* token = static_cast<size_t*>(raw); if (*token == correct_token) { *token = 0xDEADBEEF; free(raw); } else if (*token == wrong_token) { *token = 0x177E6A7; std::cerr << ERR << "wrong form of delete\n"; } else { std::cerr << ERR << "double delete\n"; } } } void* operator new(size_t size) throw (std::bad_alloc) { return allocate(size, "non-array memory", 0x5AFE6A8D); } void* operator new[](size_t size) throw (std::bad_alloc) { return allocate(size, " array memory", 0x5AFE6A8E); } void operator delete(void* payload) throw () { release(payload, "non-array memory", 0x5AFE6A8D, 0x5AFE6A8E); } void operator delete[](void* payload) throw () { release(payload, " array memory", 0x5AFE6A8E, 0x5AFE6A8D); }

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• How do you calculate the storage size of a SimpleDB domain?

  - by C. Dragon 76

  The official documentation states: Raw byte size (GB) of all item IDs + 45 bytes per item + Raw byte size (GB) of all attribute names + 45 bytes per attribute name + Raw byte size (GB) of all attribute-value pairs + 45 bytes per attribute-value pair What is the raw size of an attribute-value pair? Is it precisely the size of the value? (I would expect so, but then why is it worded "attribute-value pair"?) Or is it the size of the attribute name plus the size of the attribute value? (In that case, there would be motivation to give your attributes really short names.) For example, what is the size of the tiny domain below? +---------------------------------------------------------+ | Item Name/ID | "Price" attribute | "Calories" attribute | |--------------+-------------------+----------------------| | "apple" | "0000.43" | "0046" | | "orange" | "0000.70" | "0053" | +---------------------------------------------------------+

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• How to reliably map vSphere disks <-> Linux devices

  - by brianmcgee

  Task at hand After a virtual disk has been added to a Linux VM on vSphere 5, we need to identify the disks in order to automate the LVM storage provision. The virtual disks may reside on different datastores (e.g. sas or flash) and although they may be of the same size, their speed may vary. So I need a method to map the vSphere disks to Linux devices. Ideas Through the vSphere API, I am able to get the device info: Data Object Type: VirtualDiskFlatVer2BackingInfo Parent Managed Object ID: vm-230 Property Path: config.hardware.device[2000].backing Properties Name Type Value ChangeId string Unset contentId string "d58ec8c12486ea55c6f6d913642e1801" datastore ManagedObjectReference:Datastore datastore-216 (W5-CFAS012-Hybrid-CL20-004) deltaDiskFormat string "redoLogFormat" deltaGrainSize int Unset digestEnabled boolean false diskMode string "persistent" dynamicProperty DynamicProperty[] Unset dynamicType string Unset eagerlyScrub boolean Unset fileName string "[W5-CFAS012-Hybrid-CL20-004] l****9-000001.vmdk" parent VirtualDiskFlatVer2BackingInfo parent split boolean false thinProvisioned boolean false uuid string "6000C295-ab45-704e-9497-b25d2ba8dc00" writeThrough boolean false And on Linux I may read the uuid strings: [root@lx***** ~]# lsscsi -t [1:0:0:0] cd/dvd ata: /dev/sr0 [2:0:0:0] disk sas:0x5000c295ab45704e /dev/sda [3:0:0:0] disk sas:0x5000c2932dfa693f /dev/sdb [3:0:1:0] disk sas:0x5000c29dcd64314a /dev/sdc As you can see, the uuid string of disk /dev/sda looks somehow familiar to the string that is visible in the VMware API. Only the first hex digit is different (5 vs. 6) and it is only present to the third hyphen. So this looks promising... Alternative idea Select disks by controller. But is it reliable that the ascending SCSI Id also matches the next vSphere virtual disk? What happens if I add another DVD-ROM drive / USB Thumb drive? This will probably introduce new SCSI devices in between. Thats the cause why I think I will discard this idea. Questions Does someone know an easier method to map vSphere disks and Linux devices? Can someone explain the differences in the uuid strings? (I think this has something to do with SAS adressing initiator and target... WWN like...) May I reliably map devices by using those uuid strings? How about SCSI virtual disks? There is no uuid visible then... This task seems to be so obvious. Why doesn't Vmware think about this and simply add a way to query the disk mapping via Vmware Tools?

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• PHP - MySQL - Select runs indefinitely

  - by John

  I have three tables listings: id, pid, beds, baths, etc, etc, etc, db locations: id, pid, zip, lat, lon, etc, etc, etc, db images id, pid, height, width, raw, etc, etc, db id, pid & db are indexed. db just references the mls provider a particular item came from. in images the raw column holds raw image data there are about 15k rows in listings/locations, and about 120k rows in images so there are multiple rows that have the same pid. when i do "select pid from listings" or "select pid from locations" the query completes successfully in about 100ms. when i do "select pid from images" it just hangs in sqlyog and never completes... i was thinking since the raw column contains alot of information that it might be trying to select that too, but my query doesn't try to select that so I can't imagine why it's taking so long... any idea why this is happening??

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• Interrupt ?13 (ah=48) - not working

  - by GLeBaTi

  I want fetch the parameters of my hard disk. Using the technique described here. This is code showing normal parameters of floppy disk: mov dl,00h mov ah,08h int 13h This is code, showing not valid parameters of hard disk (may be, my hard disk space is big (LBA)): mov dl,80h mov ah,08h int 13h And I've written this code: mov dl,80h mov ah,48h int 13h The code is giving cf = 1(error). How do I fix it?

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• drupal: [title] token... not filtered !?!

  - by Patrick

  hi, I'm using path auto module to automatically stores images in the projects subfolder. I'm using the [title] token and I had a unpleasent surprise: the title "abc / dce", creates 2 folders. I was not expecting this because in the pattern descrition, [title] is clearly distinguished by [title-raw]. [title] Node title [title-raw] Unfiltered node title. WARNING - raw user input. So, how can I fix this issue, I would like to use the title I have in the url "abc-dce" thanks

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• Windows 2008 Unknown Disks

  - by Ailbe

  I have a BL460c G7 blade server with OS Windows 2008 R2 SP1. This is a brand new C7000 enclosure, with FlexFabric interconnects. I got my FC switches setup and zoned properly to our Clariion CX4, and can see all the hosts that are assigned FCoE HBAs on both paths in both Navisphere and in HP Virtual Connect Manager. So I went ahead and created a storage group for a test server, assigned the appropriate host, assigned the LUN to the server. So far so good, log onto server and I can see 4 unknown disks.... No problem, I install MS MPIO, no luck, can't initialize the disks, and the multiple disks don't go away. Still no problem, I install PowerPath version 5.5 reboot. Now I see 3 disks. One is initialized and ready to go, but I still have 2 disks that I can't initialize, can't offline, can't delete. If I right click in storage manager and go to properties I can see that the MS MPIO tab, but I can't make a path active. I want to get rid of these phantom disks, but so far nothing is working and google searches are showing up some odd results, so obviously I'm not framing my question right. I thought I'd ask here real quick. Does anyone know a quick way to get rid of these unknown disks. Another question, do I need the MPIO feature installed if I have PowerPath installed? This is my first time installing Windows 2008 R2 in this fashion and I'm not sure if that feature is needed or not right now. So some more information to add to this. It seems I'm dealing with more of a Windows issue than anything else. I removed the LUN from the server, uninstalled PowerPath completely, removed the MPIO feature from the server, and rebooted twice. Now I am back to the original 4 Unknown Disks (plus the local Disk 0 containing the OS partition of course, which is working fine) I went to diskpart, I could see all 4 Unknown disks, I selected each disk, ran clean (just in case i'd somehow brought them online previously as GPT and didn't realize it) After a few minutes I was no longer able to see the disks when I ran list disk. However, the disks are still in Disk Management. When I try and offline the disks from Disk Management I get an error: Virtual Disk Manager - The system cannot find the file specified. Accompanied by an error in System Event Logs: Log Name: System Source: Virtual Disk Service Date: 6/25/2012 4:02:01 PM Event ID: 1 Task Category: None Level: Error Keywords: Classic User: N/A Computer: hostname.local Description: Unexpected failure. Error code: 2@02000018 Event Xml: 1 2 0 0x80000000000000 4239 System hostname.local 2@02000018 I feel sure there is a place I can go in the Registry to get rid of these, I just can't recall where and I am loathe to experiement. So to recap, there are currently no LUNS attached at all, I still have the phantom disks, and I'm getting The system cannot find the file specified from Virtual Disk Manager when I try to take them offline. Thanks!

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• Kernel panic when bringing up DRBD resource

  - by sc.

  I'm trying to set up two machines synchonizing with DRBD. The storage is setup as follows: PV - LVM - DRBD - CLVM - GFS2. DRBD is set up in dual primary mode. The first server is set up and running fine in primary mode. The drives on the first server have data on them. I've set up the second server and I'm trying to bring up the DRBD resources. I created all the base LVM's to match the first server. After initializing the resources with `` drbdadm create-md storage I'm bringing up the resources by issuing drbdadm up storage After issuing that command, I get a kernel panic and the server reboots in 30 seconds. Here's a screen capture. My configuration is as follows: OS: CentOS 6 uname -a Linux host.structuralcomponents.net 2.6.32-279.5.2.el6.x86_64 #1 SMP Fri Aug 24 01:07:11 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux rpm -qa | grep drbd kmod-drbd84-8.4.1-2.el6.elrepo.x86_64 drbd84-utils-8.4.1-2.el6.elrepo.x86_64 cat /etc/drbd.d/global_common.conf global { usage-count yes; # minor-count dialog-refresh disable-ip-verification } common { handlers { pri-on-incon-degr "/usr/lib/drbd/notify-pri-on-incon-degr.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b /proc/sysrq-trigger ; reboot -f"; pri-lost-after-sb "/usr/lib/drbd/notify-pri-lost-after-sb.sh; /usr/lib/drbd/notify-emergency-reboot.sh; echo b /proc/sysrq-trigger ; reboot -f"; local-io-error "/usr/lib/drbd/notify-io-error.sh; /usr/lib/drbd/notify-emergency-shutdown.sh; echo o /proc/sysrq-trigger ; halt -f"; # fence-peer "/usr/lib/drbd/crm-fence-peer.sh"; # split-brain "/usr/lib/drbd/notify-split-brain.sh root"; # out-of-sync "/usr/lib/drbd/notify-out-of-sync.sh root"; # before-resync-target "/usr/lib/drbd/snapshot-resync-target-lvm.sh -p 15 -- -c 16k"; # after-resync-target /usr/lib/drbd/unsnapshot-resync-target-lvm.sh; } startup { # wfc-timeout degr-wfc-timeout outdated-wfc-timeout wait-after-sb become-primary-on both; wfc-timeout 30; degr-wfc-timeout 10; outdated-wfc-timeout 10; } options { # cpu-mask on-no-data-accessible } disk { # size max-bio-bvecs on-io-error fencing disk-barrier disk-flushes # disk-drain md-flushes resync-rate resync-after al-extents # c-plan-ahead c-delay-target c-fill-target c-max-rate # c-min-rate disk-timeout } net { # protocol timeout max-epoch-size max-buffers unplug-watermark # connect-int ping-int sndbuf-size rcvbuf-size ko-count # allow-two-primaries cram-hmac-alg shared-secret after-sb-0pri # after-sb-1pri after-sb-2pri always-asbp rr-conflict # ping-timeout data-integrity-alg tcp-cork on-congestion # congestion-fill congestion-extents csums-alg verify-alg # use-rle protocol C; allow-two-primaries yes; after-sb-0pri discard-zero-changes; after-sb-1pri discard-secondary; after-sb-2pri disconnect; } } cat /etc/drbd.d/storage.res resource storage { device /dev/drbd0; meta-disk internal; on host.structuralcomponents.net { address 10.10.1.120:7788; disk /dev/vg_storage/lv_storage; } on host2.structuralcomponents.net { address 10.10.1.121:7788; disk /dev/vg_storage/lv_storage; } /var/log/messages is not logging anything about the crash. I've been trying to find a cause of this but I've come up with nothing. Can anyone help me out? Thanks.

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• Grub 'Read Error' - Only Loads with LiveCD

  - by Ryan Sharp

  Problem After installing Ubuntu to complete my Windows 7/Ubuntu 12.04 dual-boot setup, Grub just wouldn't load at all unless I boot from the LiveCD. Afterwards, everything works completely normal. However, this workaround isn't a solution and I'd like to be able to boot without the aid of a disc. Fdisk -l Using the fdisk -l command, I am given the following: Disk /dev/sda: 64.0 GB, 64023257088 bytes 255 heads, 63 sectors/track, 7783 cylinders, total 125045424 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x324971d1 Device Boot Start End Blocks Id System /dev/sda1 2048 206847 102400 7 HPFS/NTFS/exFAT /dev/sda2 208896 48957439 24374272 7 HPFS/NTFS/exFAT /dev/sda3 * 48959486 124067839 37554177 5 Extended /dev/sda5 48959488 124067839 37554176 83 Linux Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xc0ee6a69 Device Boot Start End Blocks Id System /dev/sdb1 1024208894 1953523711 464657409 5 Extended /dev/sdb3 * 2048 1024206847 512102400 7 HPFS/NTFS/exFAT /dev/sdb5 1024208896 1937897471 456844288 83 Linux /dev/sdb6 1937899520 1953523711 7812096 82 Linux swap / Solaris Partition table entries are not in disk order Disk /dev/sdc: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x292eee23 Device Boot Start End Blocks Id System /dev/sdc1 2048 625141759 312569856 7 HPFS/NTFS/exFAT Bootinfoscript I've used the BootInfoScript, and received the following output: Boot Info Script 0.61 [1 April 2012] ============================= Boot Info Summary: =============================== => Grub2 (v1.99) is installed in the MBR of /dev/sda and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos5)/boot/grub on this drive. => Grub2 (v1.99) is installed in the MBR of /dev/sdb and looks at sector 1 of the same hard drive for core.img. core.img is at this location and looks for (,msdos5)/boot/grub on this drive. => Windows is installed in the MBR of /dev/sdc. sda1: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: /bootmgr /Boot/BCD sda2: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Windows 7 Boot files: /bootmgr /Boot/BCD /Windows/System32/winload.exe sda3: __________________________________________________________________________ File system: Extended Partition Boot sector type: Unknown Boot sector info: sda5: __________________________________________________________________________ File system: ext4 Boot sector type: - Boot sector info: Operating System: Ubuntu 12.04.1 LTS Boot files: /boot/grub/grub.cfg /etc/fstab /boot/grub/core.img sdb1: __________________________________________________________________________ File system: Extended Partition Boot sector type: - Boot sector info: sdb5: __________________________________________________________________________ File system: ext4 Boot sector type: - Boot sector info: Operating System: Boot files: sdb6: __________________________________________________________________________ File system: swap Boot sector type: - Boot sector info: sdb3: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: According to the info in the boot sector, sdb3 starts at sector 200744960. But according to the info from fdisk, sdb3 starts at sector 2048. According to the info in the boot sector, sdb3 has 823461887 sectors, but according to the info from fdisk, it has 1024204799 sectors. Operating System: Boot files: sdc1: __________________________________________________________________________ File system: ntfs Boot sector type: Windows Vista/7: NTFS Boot sector info: No errors found in the Boot Parameter Block. Operating System: Boot files: ============================ Drive/Partition Info: ============================= Drive: sda _____________________________________________________________________ Disk /dev/sda: 64.0 GB, 64023257088 bytes 255 heads, 63 sectors/track, 7783 cylinders, total 125045424 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sda1 2,048 206,847 204,800 7 NTFS / exFAT / HPFS /dev/sda2 208,896 48,957,439 48,748,544 7 NTFS / exFAT / HPFS /dev/sda3 * 48,959,486 124,067,839 75,108,354 5 Extended /dev/sda5 48,959,488 124,067,839 75,108,352 83 Linux Drive: sdb _____________________________________________________________________ Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sdb1 1,024,208,894 1,953,523,711 929,314,818 5 Extended /dev/sdb5 1,024,208,896 1,937,897,471 913,688,576 83 Linux /dev/sdb6 1,937,899,520 1,953,523,711 15,624,192 82 Linux swap / Solaris /dev/sdb3 * 2,048 1,024,206,847 1,024,204,800 7 NTFS / exFAT / HPFS Drive: sdc _____________________________________________________________________ Disk /dev/sdc: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes Partition Boot Start Sector End Sector # of Sectors Id System /dev/sdc1 2,048 625,141,759 625,139,712 7 NTFS / exFAT / HPFS "blkid" output: ________________________________________________________________ Device UUID TYPE LABEL /dev/sda1 A48056DF8056B80E ntfs System Reserved /dev/sda2 A8C6D6A4C6D671D4 ntfs Windows /dev/sda5 fd71c537-3715-44e1-b1fe-07537e22b3dd ext4 /dev/sdb3 6373D03D0A3747A8 ntfs Steam /dev/sdb5 6f5a6eb3-a932-45aa-893e-045b57708270 ext4 /dev/sdb6 469848c8-867a-41b7-b0e1-b813a43c64af swap /dev/sdc1 725D7B961CF34B1B ntfs backup ================================ Mount points: ================================= Device Mount_Point Type Options /dev/sda5 / ext4 (rw,noatime,nodiratime,discard,errors=remount-ro) /dev/sdb5 /home ext4 (rw) =========================== sda5/boot/grub/grub.cfg: =========================== -------------------------------------------------------------------------------- # # DO NOT EDIT THIS FILE # # It is automatically generated by grub-mkconfig using templates # from /etc/grub.d and settings from /etc/default/grub # ### BEGIN /etc/grub.d/00_header ### if [ -s $prefix/grubenv ]; then set have_grubenv=true load_env fi set default="0" if [ "${prev_saved_entry}" ]; then set saved_entry="${prev_saved_entry}" save_env saved_entry set prev_saved_entry= save_env prev_saved_entry set boot_once=true fi function savedefault { if [ -z "${boot_once}" ]; then saved_entry="${chosen}" save_env saved_entry fi } function recordfail { set recordfail=1 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi } function load_video { insmod vbe insmod vga insmod video_bochs insmod video_cirrus } insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set=root fd71c537-3715-44e1-b1fe-07537e22b3dd if loadfont /usr/share/grub/unicode.pf2 ; then set gfxmode=auto load_video insmod gfxterm insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set=root fd71c537-3715-44e1-b1fe-07537e22b3dd set locale_dir=($root)/boot/grub/locale set lang=en_GB insmod gettext fi terminal_output gfxterm if [ "${recordfail}" = 1 ]; then set timeout=-1 else set timeout=10 fi ### END /etc/grub.d/00_header ### ### BEGIN /etc/grub.d/05_debian_theme ### set menu_color_normal=white/black set menu_color_highlight=black/light-gray if background_color 44,0,30; then clear fi ### END /etc/grub.d/05_debian_theme ### ### BEGIN /etc/grub.d/10_linux ### function gfxmode { set gfxpayload="${1}" if [ "${1}" = "keep" ]; then set vt_handoff=vt.handoff=7 else set vt_handoff= fi } if [ "${recordfail}" != 1 ]; then if [ -e ${prefix}/gfxblacklist.txt ]; then if hwmatch ${prefix}/gfxblacklist.txt 3; then if [ ${match} = 0 ]; then set linux_gfx_mode=keep else set linux_gfx_mode=text fi else set linux_gfx_mode=text fi else set linux_gfx_mode=keep fi else set linux_gfx_mode=text fi export linux_gfx_mode if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi menuentry 'Ubuntu, with Linux 3.2.0-29-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail gfxmode $linux_gfx_mode insmod gzio insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set=root fd71c537-3715-44e1-b1fe-07537e22b3dd linux /boot/vmlinuz-3.2.0-29-generic root=UUID=fd71c537-3715-44e1-b1fe-07537e22b3dd ro quiet splash $vt_handoff initrd /boot/initrd.img-3.2.0-29-generic } menuentry 'Ubuntu, with Linux 3.2.0-29-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { recordfail insmod gzio insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set=root fd71c537-3715-44e1-b1fe-07537e22b3dd echo 'Loading Linux 3.2.0-29-generic ...' linux /boot/vmlinuz-3.2.0-29-generic root=UUID=fd71c537-3715-44e1-b1fe-07537e22b3dd ro recovery nomodeset echo 'Loading initial ramdisk ...' initrd /boot/initrd.img-3.2.0-29-generic } ### END /etc/grub.d/10_linux ### ### BEGIN /etc/grub.d/20_linux_xen ### ### END /etc/grub.d/20_linux_xen ### ### BEGIN /etc/grub.d/20_memtest86+ ### menuentry "Memory test (memtest86+)" { insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set=root fd71c537-3715-44e1-b1fe-07537e22b3dd linux16 /boot/memtest86+.bin } menuentry "Memory test (memtest86+, serial console 115200)" { insmod part_msdos insmod ext2 set root='(hd0,msdos5)' search --no-floppy --fs-uuid --set=root fd71c537-3715-44e1-b1fe-07537e22b3dd linux16 /boot/memtest86+.bin console=ttyS0,115200n8 } ### END /etc/grub.d/20_memtest86+ ### ### BEGIN /etc/grub.d/30_os-prober ### menuentry "Windows 7 (loader) (on /dev/sda1)" --class windows --class os { insmod part_msdos insmod ntfs set root='(hd0,msdos1)' search --no-floppy --fs-uuid --set=root A48056DF8056B80E chainloader +1 } menuentry "Windows 7 (loader) (on /dev/sda2)" --class windows --class os { insmod part_msdos insmod ntfs set root='(hd0,msdos2)' search --no-floppy --fs-uuid --set=root A8C6D6A4C6D671D4 chainloader +1 } ### END /etc/grub.d/30_os-prober ### ### BEGIN /etc/grub.d/40_custom ### # This file provides an easy way to add custom menu entries. Simply type the # menu entries you want to add after this comment. Be careful not to change # the 'exec tail' line above. ### END /etc/grub.d/40_custom ### ### BEGIN /etc/grub.d/41_custom ### if [ -f $prefix/custom.cfg ]; then source $prefix/custom.cfg; fi ### END /etc/grub.d/41_custom ### -------------------------------------------------------------------------------- =============================== sda5/etc/fstab: ================================ -------------------------------------------------------------------------------- # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # <file system> <mount point> <type> <options> <dump> <pass> proc /proc proc nodev,noexec,nosuid 0 0 # / was on /dev/sda5 during installation UUID=fd71c537-3715-44e1-b1fe-07537e22b3dd / ext4 noatime,nodiratime,discard,errors=remount-ro 0 1 # /home was on /dev/sdb5 during installation UUID=6f5a6eb3-a932-45aa-893e-045b57708270 /home ext4 defaults 0 2 # swap was on /dev/sdb6 during installation UUID=469848c8-867a-41b7-b0e1-b813a43c64af none swap sw 0 0 tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0 -------------------------------------------------------------------------------- =================== sda5: Location of files loaded by Grub: ==================== GiB - GB File Fragment(s) = boot/grub/core.img 1 = boot/grub/grub.cfg 1 = boot/initrd.img-3.2.0-29-generic 2 = boot/vmlinuz-3.2.0-29-generic 1 = initrd.img 2 = vmlinuz 1 ======================== Unknown MBRs/Boot Sectors/etc: ======================== Unknown BootLoader on sda3 00000000 63 6f 70 69 61 20 65 20 63 6f 6c 61 41 63 65 64 |copia e colaAced| 00000010 65 72 20 61 20 74 6f 64 6f 20 6f 20 74 65 78 74 |er a todo o text| 00000020 6f 20 66 61 6c 61 64 6f 20 75 74 69 6c 69 7a 61 |o falado utiliza| 00000030 6e 64 6f 20 61 20 63 6f 6e 76 65 72 73 c3 a3 6f |ndo a convers..o| 00000040 20 64 65 20 74 65 78 74 6f 20 70 61 72 61 20 76 | de texto para v| 00000050 6f 7a 4d 61 6e 69 70 75 6c 61 72 20 61 73 20 64 |ozManipular as d| 00000060 65 66 69 6e 69 c3 a7 c3 b5 65 73 20 71 75 65 20 |efini....es que | 00000070 63 6f 6e 74 72 6f 6c 61 6d 20 6f 20 61 63 65 73 |controlam o aces| 00000080 73 6f 20 64 65 20 57 65 62 73 69 74 65 73 20 61 |so de Websites a| 00000090 20 63 6f 6f 6b 69 65 73 2c 20 4a 61 76 61 53 63 | cookies, JavaSc| 000000a0 72 69 70 74 20 65 20 70 6c 75 67 2d 69 6e 73 4d |ript e plug-insM| 000000b0 61 6e 69 70 75 6c 61 72 20 61 73 20 64 65 66 69 |anipular as defi| 000000c0 6e 69 c3 a7 c3 b5 65 73 20 72 65 6c 61 63 69 6f |ni....es relacio| 000000d0 6e 61 64 61 73 20 63 6f 6d 20 70 72 69 76 61 63 |nadas com privac| 000000e0 69 64 61 64 65 41 63 65 64 65 72 20 61 6f 73 20 |idadeAceder aos | 000000f0 73 65 75 73 20 70 65 72 69 66 c3 a9 72 69 63 6f |seus perif..rico| 00000100 73 20 55 53 42 55 74 69 6c 69 7a 61 72 20 6f 20 |s USBUtilizar o | 00000110 73 65 75 20 6d 69 63 72 6f 66 6f 6e 65 55 74 69 |seu microfoneUti| 00000120 6c 69 7a 61 72 20 61 20 73 75 61 20 63 c3 a2 6d |lizar a sua c..m| 00000130 61 72 61 55 74 69 6c 69 7a 61 72 20 6f 20 73 65 |araUtilizar o se| 00000140 75 20 6d 69 63 72 6f 66 6f 6e 65 20 65 20 61 20 |u microfone e a | 00000150 63 c3 a2 6d 61 72 61 4e c3 a3 6f 20 66 6f 69 20 |c..maraN..o foi | 00000160 70 6f 73 73 c3 ad 76 65 6c 20 65 6e 63 6f 6e 74 |poss..vel encont| 00000170 72 61 72 20 6f 20 63 61 6d 69 6e 68 6f 20 61 62 |rar o caminho ab| 00000180 73 6f 6c 75 74 6f 20 70 61 72 61 20 6f 20 64 69 |soluto para o di| 00000190 72 65 63 74 c3 b3 72 69 6f 20 61 20 65 6d 70 61 |rect..rio a empa| 000001a0 63 6f 74 61 72 2e 4f 20 64 69 72 65 63 74 c3 b3 |cotar.O direct..| 000001b0 72 69 6f 20 64 65 20 65 6e 74 72 61 64 61 00 fe |rio de entrada..| 000001c0 ff ff 83 fe ff ff 02 00 00 00 00 10 7a 04 00 00 |............z...| 000001d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000001f0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 55 aa |..............U.| 00000200 =============================== StdErr Messages: =============================== xz: (stdin): Compressed data is corrupt xz: (stdin): Compressed data is corrupt awk: cmd. line:36: Math support is not compiled in awk: cmd. line:36: Math support is not compiled in awk: cmd. line:36: Math support is not compiled in awk: cmd. line:36: Math support is not compiled in awk: cmd. line:36: Math support is not compiled in awk: cmd. line:36: Math support is not compiled in Begging / Appreciation ;) If anything else is required to solve my problem, please ask. My only hopes are that I can solve this, and that doing so won't require re-installation of Grub due to how complicated the procedures are, or that I would be needed to reinstall the OS', as I have done so about six times already since friday due to several other issues I've encountered. Thank you, and good day. System Ubuntu 12.04 64-bit / Windows 7 SP1 64-bit 64GB SSD as boot/OS drive, 1TB HDD as /Home Swap and Steam drive.

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• How to disable Mac OS X from using swap when there still is "Inactive" memory?

  - by Motin

  A common phenomena in my day to day usage (and several other's according to various posts throughout the internet) of OS X, the system seems to become slow whenever there is no more "Free" memory available. Supposedly, this is due to swapping, since heavy disk activity is apparent and that vm_stat reports many pageouts. (Correct me from wrong) However, the amount of "Inactive" ram is typically around 12.5%-25% of all available memory (^1.) when swapping starts/occurs/ends. According to http://support.apple.com/kb/ht1342 : Inactive memory This information in memory is not actively being used, but was recently used. For example, if you've been using Mail and then quit it, the RAM that Mail was using is marked as Inactive memory. This Inactive memory is available for use by another application, just like Free memory. However, if you open Mail before its Inactive memory is used by a different application, Mail will open quicker because its Inactive memory is converted to Active memory, instead of loading Mail from the slower hard disk. And according to http://developer.apple.com/library/mac/#documentation/Performance/Conceptual/ManagingMemory/Articles/AboutMemory.html : The inactive list contains pages that are currently resident in physical memory but have not been accessed recently. These pages contain valid data but may be released from memory at any time. So, basically: When a program has quit, it's memory becomes marked as Inactive and should be claimable at any time. Still, OS X will prefer to start swapping out memory to the Swap file instead of just claiming this memory, whenever the "Free" memory gets to low. Why? What is the advantage of this behavior over, say, instantly releasing Inactive memory and not even touch the swap file? Some sources (^2.) indicate that OS X would page out the "Inactive" memory to swap before releasing it, but that doesn't make sense now does it if the memory may be released from memory at any time? Swapping is expensive, releasing is cheap, right? Can this behavior be changed using some preference or known hack? (Preferably one that doesn't include disabling swap/dynamic_pager altogether and restarting...) I do appreciate the purge command, as well as the concept of Repairing disk permissions to force some Free memory, but those are ways to painfully force more Free memory than to actually fixing the swap/release decision logic... Btw a similar question was asked here: http://forums.macnn.com/90/mac-os-x/434650/why-does-os-x-swap-when/ and here: http://hintsforums.macworld.com/showthread.php?t=87688 but even though the OPs re-asked the core question, none of the replies addresses an answer to it... ^1. UPDATE 17-mar-2012 Since I first posted this question, I have gone from 4gb to 8gb of installed ram, and the problem remains. The amount of "Inactive" ram was 0.5gb-1.0gb before and is now typically around 1.0-2.0GB when swapping starts/occurs/ends, ie it seems that around 12.5%-25% of the ram is preserved as Inactive by osx kernel logic. ^2. For instance http://apple.stackexchange.com/questions/4288/what-does-it-mean-if-i-have-lots-of-inactive-memory-at-the-end-of-a-work-day : Once all your memory is used (free memory is 0), the OS will write out inactive memory to the swapfile to make more room in active memory. UPDATE 17-mar-2012 Here is a round-up of the methods that have been suggested to help so far: The purge command "Used to approximate initial boot conditions with a cold disk buffer cache for performance analysis. It does not affect anonymous memory that has been allocated through malloc, vm_allocate, etc". This is useful to prevent osx to swap-out the disk cache (which is ridiculous that osx actually does so in the first place), but with the downside that the disk cache is released, meaning that if the disk cache was not about to be swapped out, one would simply end up with a cold disk buffer cache, probably affecting performance negatively. The FreeMemory app and/or Repairing disk permissions to force some Free memory Doesn't help releasing any memory, only moving some gigabytes of memory contents from ram to the hd. In the end, this causes lots of swap-ins when I attempt to use the applications that were open while freeing memory, as a lot of its vm is now on swap. Speeding up swap-allocation using dynamicpagerwrapper Seems a good thing to do in order to speed up swap-usage, but does not address the problem of osx swapping in the first place while there is still inactive memory. Disabling swap by disabling dynamicpager and restarting This will force osx not to use swap to the price of the system hanging when all memory is used. Not a viable alternative... Disabling swap using a hacked dynamicpager Similar to disabling dynamicpager above, some excerpts from the comments to the blog post indicate that this is not a viable solution: "The Inactive Memory is high as usual". "when your system is running out of memory, the whole os hangs...", "if you consume the whole amount of memory of the mac, the machine will likely hang" To sum up, I am still unaware of a way of disabling Mac OS X from using swap when there still is "Inactive" memory. If it isn't possible, maybe at least there is an explanation somewhere of why osx prefers to swap out memory that may be released from memory at any time?

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• What's up with LDoms: Part 1 - Introduction & Basic Concepts

  - by Stefan Hinker

  LDoms - the correct name is Oracle VM Server for SPARC - have been around for quite a while now.  But to my surprise, I get more and more requests to explain how they work or to give advise on how to make good use of them.  This made me think that writing up a few articles discussing the different features would be a good idea.  Now - I don't intend to rewrite the LDoms Admin Guide or to copy and reformat the (hopefully) well known "Beginners Guide to LDoms" by Tony Shoumack from 2007.  Those documents are very recommendable - especially the Beginners Guide, although based on LDoms 1.0, is still a good place to begin with.  However, LDoms have come a long way since then, and I hope to contribute to their adoption by discussing how they work and what features there are today.  In this and the following posts, I will use the term "LDoms" as a common abbreviation for Oracle VM Server for SPARC, just because it's a lot shorter and easier to type (and presumably, read). So, just to get everyone on the same baseline, lets briefly discuss the basic concepts of virtualization with LDoms.  LDoms make use of a hypervisor as a layer of abstraction between real, physical hardware and virtual hardware.  This virtual hardware is then used to create a number of guest systems which each behave very similar to a system running on bare metal:  Each has its own OBP, each will install its own copy of the Solaris OS and each will see a certain amount of CPU, memory, disk and network resources available to it.  Unlike some other type 1 hypervisors running on x86 hardware, the SPARC hypervisor is embedded in the system firmware and makes use both of supporting functions in the sun4v SPARC instruction set as well as the overall CPU architecture to fulfill its function. The CMT architecture of the supporting CPUs (T1 through T4) provide a large number of cores and threads to the OS.  For example, the current T4 CPU has eight cores, each running 8 threads, for a total of 64 threads per socket.  To the OS, this looks like 64 CPUs.  The SPARC hypervisor, when creating guest systems, simply assigns a certain number of these threads exclusively to one guest, thus avoiding the overhead of having to schedule OS threads to CPUs, as do typical x86 hypervisors.  The hypervisor only assigns CPUs and then steps aside.  It is not involved in the actual work being dispatched from the OS to the CPU, all it does is maintain isolation between different guests. Likewise, memory is assigned exclusively to individual guests.  Here,  the hypervisor provides generic mappings between the physical hardware addresses and the guest's views on memory.  Again, the hypervisor is not involved in the actual memory access, it only maintains isolation between guests. During the inital setup of a system with LDoms, you start with one special domain, called the Control Domain.  Initially, this domain owns all the hardware available in the system, including all CPUs, all RAM and all IO resources.  If you'd be running the system un-virtualized, this would be what you'd be working with.  To allow for guests, you first resize this initial domain (also called a primary domain in LDoms speak), assigning it a small amount of CPU and memory.  This frees up most of the available CPU and memory resources for guest domains.  IO is a little more complex, but very straightforward.  When LDoms 1.0 first came out, the only way to provide IO to guest systems was to create virtual disk and network services and attach guests to these services.  In the meantime, several different ways to connect guest domains to IO have been developed, the most recent one being SR-IOV support for network devices released in version 2.2 of Oracle VM Server for SPARC. I will cover these more advanced features in detail later.  For now, lets have a short look at the initial way IO was virtualized in LDoms: For virtualized IO, you create two services, one "Virtual Disk Service" or vds, and one "Virtual Switch" or vswitch.  You can, of course, also create more of these, but that's more advanced than I want to cover in this introduction.  These IO services now connect real, physical IO resources like a disk LUN or a networt port to the virtual devices that are assigned to guest domains.  For disk IO, the normal case would be to connect a physical LUN (or some other storage option that I'll discuss later) to one specific guest.  That guest would be assigned a virtual disk, which would appear to be just like a real LUN to the guest, while the IO is actually routed through the virtual disk service down to the physical device.  For network, the vswitch acts very much like a real, physical ethernet switch - you connect one physical port to it for outside connectivity and define one or more connections per guest, just like you would plug cables between a real switch and a real system. For completeness, there is another service that provides console access to guest domains which mimics the behavior of serial terminal servers. The connections between the virtual devices on the guest's side and the virtual IO services in the primary domain are created by the hypervisor.  It uses so called "Logical Domain Channels" or LDCs to create point-to-point connections between all of these devices and services.  These LDCs work very similar to high speed serial connections and are configured automatically whenever the Control Domain adds or removes virtual IO. To see all this in action, now lets look at a first example.  I will start with a newly installed machine and configure the control domain so that it's ready to create guest systems. In a first step, after we've installed the software, let's start the virtual console service and downsize the primary domain.  root@sun # ldm list NAME STATE FLAGS CONS VCPU MEMORY UTIL UPTIME primary active -n-c-- UART 512 261632M 0.3% 2d 13h 58m root@sun # ldm add-vconscon port-range=5000-5100 \ primary-console primary root@sun # svcadm enable vntsd root@sun # svcs vntsd STATE STIME FMRI online 9:53:21 svc:/ldoms/vntsd:default root@sun # ldm set-vcpu 16 primary root@sun # ldm set-mau 1 primary root@sun # ldm start-reconf primary root@sun # ldm set-memory 7680m primary root@sun # ldm add-config initial root@sun # shutdown -y -g0 -i6 So what have I done: I've defined a range of ports (5000-5100) for the virtual network terminal service and then started that service.  The vnts will later provide console connections to guest systems, very much like serial NTS's do in the physical world. Next, I assigned 16 vCPUs (on this platform, a T3-4, that's two cores) to the primary domain, freeing the rest up for future guest systems.  I also assigned one MAU to this domain.  A MAU is a crypto unit in the T3 CPU.  These need to be explicitly assigned to domains, just like CPU or memory.  (This is no longer the case with T4 systems, where crypto is always available everywhere.) Before I reassigned the memory, I started what's called a "delayed reconfiguration" session.  That avoids actually doing the change right away, which would take a considerable amount of time in this case.  Instead, I'll need to reboot once I'm all done.  I've assigned 7680MB of RAM to the primary.  That's 8GB less the 512MB which the hypervisor uses for it's own private purposes.  You can, depending on your needs, work with less.  I'll spend a dedicated article on sizing, discussing the pros and cons in detail. Finally, just before the reboot, I saved my work on the ILOM, to make this configuration available after a powercycle of the box.  (It'll always be available after a simple reboot, but the ILOM needs to know the configuration of the hypervisor after a power-cycle, before the primary domain is booted.) Now, lets create a first disk service and a first virtual switch which is connected to the physical network device igb2. We will later use these to connect virtual disks and virtual network ports of our guest systems to real world storage and network. root@sun # ldm add-vds primary-vds root@sun # ldm add-vswitch net-dev=igb2 switch-primary primary You are free to choose whatever names you like for the virtual disk service and the virtual switch.  I strongly recommend that you choose names that make sense to you and describe the function of each service in the context of your implementation.  For the vswitch, for example, you could choose names like "admin-vswitch" or "production-network" etc. This already concludes the configuration of the control domain.  We've freed up considerable amounts of CPU and RAM for guest systems and created the necessary infrastructure - console, vts and vswitch - so that guests systems can actually interact with the outside world.  The system is now ready to create guests, which I'll describe in the next section. For further reading, here are some recommendable links: The LDoms 2.2 Admin Guide The "Beginners Guide to LDoms" The LDoms Information Center on MOS LDoms on OTN

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• Commit in SQL

  - by PRajkumar

  SQL Transaction Control Language Commands (TCL)                                           (COMMIT) Commit Transaction As a SQL language we use transaction control language very frequently. Committing a transaction means making permanent the changes performed by the SQL statements within the transaction. A transaction is a sequence of SQL statements that Oracle Database treats as a single unit. This statement also erases all save points in the transaction and releases transaction locks. Oracle Database issues an implicit COMMIT before and after any data definition language (DDL) statement. Oracle recommends that you explicitly end every transaction in your application programs with a COMMIT or ROLLBACK statement, including the last transaction, before disconnecting from Oracle Database. If you do not explicitly commit the transaction and the program terminates abnormally, then the last uncommitted transaction is automatically rolled back.   Until you commit a transaction: ·         You can see any changes you have made during the transaction by querying the modified tables, but other users cannot see the changes. After you commit the transaction, the changes are visible to other users' statements that execute after the commit ·         You can roll back (undo) any changes made during the transaction with the ROLLBACK statement   Note: Most of the people think that when we type commit data or changes of what you have made has been written to data files, but this is wrong when you type commit it means that you are saying that your job has been completed and respective verification will be done by oracle engine that means it checks whether your transaction achieved consistency when it finds ok it sends a commit message to the user from log buffer but not from data buffer, so after writing data in log buffer it insists data buffer to write data in to data files, this is how it works.   Before a transaction that modifies data is committed, the following has occurred: ·         Oracle has generated undo information. The undo information contains the old data values changed by the SQL statements of the transaction ·         Oracle has generated redo log entries in the redo log buffer of the System Global Area (SGA). The redo log record contains the change to the data block and the change to the rollback block. These changes may go to disk before a transaction is committed ·         The changes have been made to the database buffers of the SGA. These changes may go to disk before a transaction is committed   Note:   The data changes for a committed transaction, stored in the database buffers of the SGA, are not necessarily written immediately to the data files by the database writer (DBWn) background process. This writing takes place when it is most efficient for the database to do so. It can happen before the transaction commits or, alternatively, it can happen some times after the transaction commits.   When a transaction is committed, the following occurs: 1.      The internal transaction table for the associated undo table space records that the transaction has committed, and the corresponding unique system change number (SCN) of the transaction is assigned and recorded in the table 2.      The log writer process (LGWR) writes redo log entries in the SGA's redo log buffers to the redo log file. It also writes the transaction's SCN to the redo log file. This atomic event constitutes the commit of the transaction 3.      Oracle releases locks held on rows and tables 4.      Oracle marks the transaction complete   Note:   The default behavior is for LGWR to write redo to the online redo log files synchronously and for transactions to wait for the redo to go to disk before returning a commit to the user. However, for lower transaction commit latency application developers can specify that redo be written asynchronously and that transaction do not need to wait for the redo to be on disk.   The syntax of Commit Statement is   COMMIT [WORK] [COMMENT ‘your comment’]; ·         WORK is optional. The WORK keyword is supported for compliance with standard SQL. The statements COMMIT and COMMIT WORK are equivalent. Examples Committing an Insert INSERT INTO table_name VALUES (val1, val2); COMMIT WORK; ·         COMMENT Comment is also optional. This clause is supported for backward compatibility. Oracle recommends that you used named transactions instead of commit comments. Specify a comment to be associated with the current transaction. The 'text' is a quoted literal of up to 255 bytes that Oracle Database stores in the data dictionary view DBA_2PC_PENDING along with the transaction ID if a distributed transaction becomes in doubt. This comment can help you diagnose the failure of a distributed transaction. Examples The following statement commits the current transaction and associates a comment with it: COMMIT     COMMENT 'In-doubt transaction Code 36, Call (415) 555-2637'; ·         WRITE Clause Use this clause to specify the priority with which the redo information generated by the commit operation is written to the redo log. This clause can improve performance by reducing latency, thus eliminating the wait for an I/O to the redo log. Use this clause to improve response time in environments with stringent response time requirements where the following conditions apply: The volume of update transactions is large, requiring that the redo log be written to disk frequently. The application can tolerate the loss of an asynchronously committed transaction. The latency contributed by waiting for the redo log write to occur contributes significantly to overall response time. You can specify the WAIT | NOWAIT and IMMEDIATE | BATCH clauses in any order. Examples To commit the same insert operation and instruct the database to buffer the change to the redo log, without initiating disk I/O, use the following COMMIT statement: COMMIT WRITE BATCH; Note: If you omit this clause, then the behavior of the commit operation is controlled by the COMMIT_WRITE initialization parameter, if it has been set. The default value of the parameter is the same as the default for this clause. Therefore, if the parameter has not been set and you omit this clause, then commit records are written to disk before control is returned to the user. WAIT | NOWAIT Use these clauses to specify when control returns to the user. The WAIT parameter ensures that the commit will return only after the corresponding redo is persistent in the online redo log. Whether in BATCH or IMMEDIATE mode, when the client receives a successful return from this COMMIT statement, the transaction has been committed to durable media. A crash occurring after a successful write to the log can prevent the success message from returning to the client. In this case the client cannot tell whether or not the transaction committed. The NOWAIT parameter causes the commit to return to the client whether or not the write to the redo log has completed. This behavior can increase transaction throughput. With the WAIT parameter, if the commit message is received, then you can be sure that no data has been lost. Caution: With NOWAIT, a crash occurring after the commit message is received, but before the redo log record(s) are written, can falsely indicate to a transaction that its changes are persistent. If you omit this clause, then the transaction commits with the WAIT behavior. IMMEDIATE | BATCH Use these clauses to specify when the redo is written to the log. The IMMEDIATE parameter causes the log writer process (LGWR) to write the transaction's redo information to the log. This operation option forces a disk I/O, so it can reduce transaction throughput. The BATCH parameter causes the redo to be buffered to the redo log, along with other concurrently executing transactions. When sufficient redo information is collected, a disk write of the redo log is initiated. This behavior is called "group commit", as redo for multiple transactions is written to the log in a single I/O operation. If you omit this clause, then the transaction commits with the IMMEDIATE behavior. ·         FORCE Clause Use this clause to manually commit an in-doubt distributed transaction or a corrupt transaction. ·         In a distributed database system, the FORCE string [, integer] clause lets you manually commit an in-doubt distributed transaction. The transaction is identified by the 'string' containing its local or global transaction ID. To find the IDs of such transactions, query the data dictionary view DBA_2PC_PENDING. You can use integer to specifically assign the transaction a system change number (SCN). If you omit integer, then the transaction is committed using the current SCN. ·         The FORCE CORRUPT_XID 'string' clause lets you manually commit a single corrupt transaction, where string is the ID of the corrupt transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to specify this clause. ·         Specify FORCE CORRUPT_XID_ALL to manually commit all corrupt transactions. You must have DBA privileges to specify this clause. Examples Forcing an in doubt transaction. Example The following statement manually commits a hypothetical in-doubt distributed transaction. Query the V$CORRUPT_XID_LIST data dictionary view to find the transaction IDs of corrupt transactions. You must have DBA privileges to view the V$CORRUPT_XID_LIST and to issue this statement. COMMIT FORCE '22.57.53';

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• SQL SERVER – Introduction to SQL Server 2014 In-Memory OLTP

  - by Pinal Dave

  In SQL Server 2014 Microsoft has introduced a new database engine component called In-Memory OLTP aka project “Hekaton” which is fully integrated into the SQL Server Database Engine. It is optimized for OLTP workloads accessing memory resident data. In-memory OLTP helps us create memory optimized tables which in turn offer significant performance improvement for our typical OLTP workload. The main objective of memory optimized table is to ensure that highly transactional tables could live in memory and remain in memory forever without even losing out a single record. The most significant part is that it still supports majority of our Transact-SQL statement. Transact-SQL stored procedures can be compiled to machine code for further performance improvements on memory-optimized tables. This engine is designed to ensure higher concurrency and minimal blocking. In-Memory OLTP alleviates the issue of locking, using a new type of multi-version optimistic concurrency control. It also substantially reduces waiting for log writes by generating far less log data and needing fewer log writes. Points to remember Memory-optimized tables refer to tables using the new data structures and key words added as part of In-Memory OLTP. Disk-based tables refer to your normal tables which we used to create in SQL Server since its inception. These tables use a fixed size 8 KB pages that need to be read from and written to disk as a unit. Natively compiled stored procedures refer to an object Type which is new and is supported by in-memory OLTP engine which convert it into machine code, which can further improve the data access performance for memory –optimized tables. Natively compiled stored procedures can only reference memory-optimized tables, they can’t be used to reference any disk –based table. Interpreted Transact-SQL stored procedures, which is what SQL Server has always used. Cross-container transactions refer to transactions that reference both memory-optimized tables and disk-based tables. Interop refers to interpreted Transact-SQL that references memory-optimized tables. Using In-Memory OLTP In-Memory OLTP engine has been available as part of SQL Server 2014 since June 2013 CTPs. Installation of In-Memory OLTP is part of the SQL Server setup application. The In-Memory OLTP components can only be installed with a 64-bit edition of SQL Server 2014 hence they are not available with 32-bit editions. Creating Databases Any database that will store memory-optimized tables must have a MEMORY_OPTIMIZED_DATA filegroup. This filegroup is specifically designed to store the checkpoint files needed by SQL Server to recover the memory-optimized tables, and although the syntax for creating the filegroup is almost the same as for creating a regular filestream filegroup, it must also specify the option CONTAINS MEMORY_OPTIMIZED_DATA. Here is an example of a CREATE DATABASE statement for a database that can support memory-optimized tables: CREATE DATABASE InMemoryDB ON PRIMARY(NAME = [InMemoryDB_data], FILENAME = 'D:\data\InMemoryDB_data.mdf', size=500MB), FILEGROUP [SampleDB_mod_fg] CONTAINS MEMORY_OPTIMIZED_DATA (NAME = [InMemoryDB_mod_dir], FILENAME = 'S:\data\InMemoryDB_mod_dir'), (NAME = [InMemoryDB_mod_dir], FILENAME = 'R:\data\InMemoryDB_mod_dir') LOG ON (name = [SampleDB_log], Filename='L:\log\InMemoryDB_log.ldf', size=500MB) COLLATE Latin1_General_100_BIN2; Above example code creates files on three different drives (D:  S: and R:) for the data files and in memory storage so if you would like to run this code kindly change the drive and folder locations as per your convenience. Also notice that binary collation was specified as Windows (non-SQL). BIN2 collation is the only collation support at this point for any indexes on memory optimized tables. It is also possible to add a MEMORY_OPTIMIZED_DATA file group to an existing database, use the below command to achieve the same. ALTER DATABASE AdventureWorks2012 ADD FILEGROUP hekaton_mod CONTAINS MEMORY_OPTIMIZED_DATA; GO ALTER DATABASE AdventureWorks2012 ADD FILE (NAME='hekaton_mod', FILENAME='S:\data\hekaton_mod') TO FILEGROUP hekaton_mod; GO Creating Tables There is no major syntactical difference between creating a disk based table or a memory –optimized table but yes there are a few restrictions and a few new essential extensions. Essentially any memory-optimized table should use the MEMORY_OPTIMIZED = ON clause as shown in the Create Table query example. DURABILITY clause (SCHEMA_AND_DATA or SCHEMA_ONLY) Memory-optimized table should always be defined with a DURABILITY value which can be either SCHEMA_AND_DATA or  SCHEMA_ONLY the former being the default. A memory-optimized table defined with DURABILITY=SCHEMA_ONLY will not persist the data to disk which means the data durability is compromised whereas DURABILITY= SCHEMA_AND_DATA ensures that data is also persisted along with the schema. Indexing Memory Optimized Table A memory-optimized table must always have an index for all tables created with DURABILITY= SCHEMA_AND_DATA and this can be achieved by declaring a PRIMARY KEY Constraint at the time of creating a table. The following example shows a PRIMARY KEY index created as a HASH index, for which a bucket count must also be specified. CREATE TABLE Mem_Table ( [Name] VARCHAR(32) NOT NULL PRIMARY KEY NONCLUSTERED HASH WITH (BUCKET_COUNT = 100000), [City] VARCHAR(32) NULL, [State_Province] VARCHAR(32) NULL, [LastModified] DATETIME NOT NULL, ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_AND_DATA); Now as you can see in the above query example we have used the clause MEMORY_OPTIMIZED = ON to make sure that it is considered as a memory optimized table and not just a normal table and also used the DURABILITY Clause= SCHEMA_AND_DATA which means it will persist data along with metadata and also you can notice this table has a PRIMARY KEY mentioned upfront which is also a mandatory clause for memory-optimized tables. We will talk more about HASH Indexes and BUCKET_COUNT in later articles on this topic which will be focusing more on Row and Index storage on Memory-Optimized tables. So stay tuned for that as well. Now as we covered the basics of Memory Optimized tables and understood the key things to remember while using memory optimized tables, let’s explore more using examples to understand the Performance gains using memory-optimized tables. I will be using the database which i created earlier in this article i.e. InMemoryDB in the below Demo Exercise. USE InMemoryDB GO -- Creating a disk based table CREATE TABLE dbo.Disktable ( Id INT IDENTITY, Name CHAR(40) ) GO CREATE NONCLUSTERED INDEX IX_ID ON dbo.Disktable (Id) GO -- Creating a memory optimized table with similar structure and DURABILITY = SCHEMA_AND_DATA CREATE TABLE dbo.Memorytable_durable ( Id INT NOT NULL PRIMARY KEY NONCLUSTERED Hash WITH (bucket_count =1000000), Name CHAR(40) ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_AND_DATA) GO -- Creating an another memory optimized table with similar structure but DURABILITY = SCHEMA_Only CREATE TABLE dbo.Memorytable_nondurable ( Id INT NOT NULL PRIMARY KEY NONCLUSTERED Hash WITH (bucket_count =1000000), Name CHAR(40) ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_only) GO -- Now insert 100000 records in dbo.Disktable and observe the Time Taken DECLARE @i_t bigint SET @i_t =1 WHILE @i_t<= 100000 BEGIN INSERT INTO dbo.Disktable(Name) VALUES('sachin' + CONVERT(VARCHAR,@i_t)) SET @i_t+=1 END -- Do the same inserts for Memory table dbo.Memorytable_durable and observe the Time Taken DECLARE @i_t bigint SET @i_t =1 WHILE @i_t<= 100000 BEGIN INSERT INTO dbo.Memorytable_durable VALUES(@i_t, 'sachin' + CONVERT(VARCHAR,@i_t)) SET @i_t+=1 END -- Now finally do the same inserts for Memory table dbo.Memorytable_nondurable and observe the Time Taken DECLARE @i_t bigint SET @i_t =1 WHILE @i_t<= 100000 BEGIN INSERT INTO dbo.Memorytable_nondurable VALUES(@i_t, 'sachin' + CONVERT(VARCHAR,@i_t)) SET @i_t+=1 END The above 3 Inserts took 1.20 minutes, 54 secs, and 2 secs respectively to insert 100000 records on my machine with 8 Gb RAM. This proves the point that memory-optimized tables can definitely help businesses achieve better performance for their highly transactional business table and memory- optimized tables with Durability SCHEMA_ONLY is even faster as it does not bother persisting its data to disk which makes it supremely fast. Koenig Solutions is one of the few organizations which offer IT training on SQL Server 2014 and all its updates. Now, I leave the decision on using memory_Optimized tables on you, I hope you like this article and it helped you understand  the fundamentals of IN-Memory OLTP . Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: PostADay, SQL, SQL Authority, SQL Performance, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Koenig

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• Is this possible to re-duplicate the hardware signal on Linux?

  - by Ted Wong

  Since that every things is a file on the UNIX system. If I have a hardware, for example, a mouse, move from left corner to right corner, it should produce some kinds of file to communicate with the system. So, if my assumption is correct, is this possible to do following things: Capture the raw data, which is about moving mouse cursor from left corner to right corner? Reduplicate the raw data, using a program, same producing speed, and data, in order to "redo" moving mouse cursor from left corner to right corner

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• Finding nuggets in ARC discussions

  - by alanc

  A bit over twenty years ago, Sun formed an Architecture Review Committee (ARC) that evaluates proposals to change interfaces between components in Sun software products. During the OpenSolaris days, we opened many of these discussions to the community. While they’re back behind closed doors, and at a different company now, we still continue to hold these reviews for the software from what’s now the Sun Systems Group division of Oracle. Recently one of these reviews was held (via e-mail discussion) to review a proposal to update our GNU findutils package to the latest upstream release. One of the upstream changes discussed was the addition of an “oldfind” program. In findutils 4.3, find was modified to use the fts() function to walk the directory tree, and oldfind was created to provide the old mechanism in case there were bugs in the new implementation that users needed to workaround. In Solaris 11 though, we still ship the find descended from SVR4 as /usr/bin/find and the GNU find is available as either /usr/bin/gfind or /usr/gnu/bin/find. This raised the discussion of if we should add oldfind, and if so what should we call it. Normally our policy is to only add the g* names for GNU commands that conflict with an existing Solaris command – for instance, we ship /usr/bin/emacs, not /usr/bin/gemacs. In this case however, that seemed like it would be more confusing to have /usr/bin/oldfind be the older version of /usr/bin/gfind not of /usr/bin/find. Thus if we shipped it, it would make more sense to call it /usr/bin/goldfind, which several ARC members noted read more naturally as “gold find” than as “g old find”. One of the concerns we often discuss in ARC is if a change is likely to be understood by users or if it will result in more calls to support. As we hit this part of the discussion on a Friday at the end of a long week, I couldn’t resist putting forth a hypothetical support call for this command: “Hello, Oracle Solaris Support, how may I help you?” “My admin is out sick, but he sent an email that he put the findutils package on our server, and I can run goldfind now. I tried it, but goldfind didn’t find gold.” “Did he get the binutils package too?” “No he just said findutils, do we need binutils?” “Well, gold comes in the binutils package, so goldfind would be able to find gold if you got that package.” “How much does Oracle charge for that package?” “It’s free for Solaris users.” “You mean Oracle ships packages of gold to customers for free?” “Yes, if you get the binutils package, it includes GNU gold.” “New gold? Is that some sort of alchemy, turning stuff into gold?” “Not new gold, gold from the GNU project.” “Oracle’s taking gold from the GNU project and shipping it to me?” “Yes, if you get binutils, that package includes gold along with the other tools from the GNU project.” “And GNU doesn’t mind Oracle taking their gold and giving it to customers?” “No, GNU is a non-profit whose goal is to share their software.” “Sharing software sure, but gold? Where does a non-profit like GNU get gold anyway?” “Oh, Google donated it to them.” “Ah! So Oracle will give me the gold that GNU got from Google!” “Yes, if you get the package from us.” “How do I get the package with the gold?” “Just run pkg install binutils and it will put it on your disk.” “We’ve got multiple disks here - which one will it put it on?” “The one with the system image - do you know which one that is? “Well the note from the admin says the system is on the first disk and the users are on the second disk.” “Okay, so it should go on the first disk then.” “And where will I find the gold?” “It will be in the /usr/bin directory.” “In the user’s bin? So thats on the second disk?” “No, it would be on the system disk, with the other development tools, like make, as, and what.” “So what’s on the first disk?” “Well if the system image is there the commands should all be there.” “All the commands? Not just what?” “Right, all the commands that come with the OS, like the shell, ps, and who.” “So who’s on the first disk too?” “Yes. Did your admin say when he’d be back?” “No, just that he had a massive headache and was going home after I tried to get him to explain this stuff to me.” “I can’t imagine why.” “Oh, is why a command too?” “No, _why was a Ruby programmer.” “Ruby? Do you give those away with the gold too?” “Yes, but it comes in the ruby package, not binutils.” “Oh, I’ll have to have my admin get that package too! Thanks!” Needless to say, we decided this might not be the best idea. Since the GNU package hasn’t had to release a serious bug fix in the new find in the past few years, the new GNU find seems pretty stable, and we always have the SVR4 find to use as a fallback in Solaris, so it didn’t seem that adding oldfind was really necessary, so we passed on including it when we update to the new findutils release. [Apologies to Abbott, Costello, their fans, and everyone who read this far. The Gold (linker) page on Wikipedia may explain some of the above, but can’t explain why goldfind is the old GNU find, but gold is the new GNU ld.]

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• Availability Best Practices on Oracle VM Server for SPARC

  - by jsavit

  This is the first of a series of blog posts on configuring Oracle VM Server for SPARC (also called Logical Domains) for availability. This series will show how to how to plan for availability, improve serviceability, avoid single points of failure, and provide resiliency against hardware and software failures. Availability is a broad topic that has filled entire books, so these posts will focus on aspects specifically related to Oracle VM Server for SPARC. The goal is to improve Reliability, Availability and Serviceability (RAS): An article defining RAS can be found here. Oracle VM Server for SPARC Principles for Availability Let's state some guiding principles for availability that apply to Oracle VM Server for SPARC: Avoid Single Points Of Failure (SPOFs). Systems should be configured so a component failure does not result in a loss of application service. The general method to avoid SPOFs is to provide redundancy so service can continue without interruption if a component fails. For a critical application there may be multiple levels of redundancy so multiple failures can be tolerated. Oracle VM Server for SPARC makes it possible to configure systems that avoid SPOFs. Configure for availability at a level of resource and effort consistent with business needs. Effort and resource should be consistent with business requirements. Production has different availability requirements than test/development, so it's worth expending resources to provide higher availability. Even within the category of production there may be different levels of criticality, outage tolerances, recovery and repair time requirements. Keep in mind that a simple design may be more understandable and effective than a complex design that attempts to "do everything". Design for availability at the appropriate tier or level of the platform stack. Availability can be provided in the application, in the database, or in the virtualization, hardware and network layers they depend on - or using a combination of all of them. It may not be necessary to engineer resilient virtualization for stateless web applications applications where availability is provided by a network load balancer, or for enterprise applications like Oracle Real Application Clusters (RAC) and WebLogic that provide their own resiliency. It's (often) the same architecture whether virtual or not: For example, providing resiliency against a lost device path or failing disk media is done for the same reasons and may use the same design whether in a domain or not. It's (often) the same technique whether using domains or not: Many configuration steps are the same. For example, configuring IPMP or creating a redundant ZFS pool is pretty much the same within the guest whether you're in a guest domain or not. There are configuration steps and choices for provisioning the guest with the virtual network and disk devices, which we will discuss. Sometimes it is different using domains: There are new resources to configure. Most notable is the use of alternate service domains, which provides resiliency in case of a domain failure, and also permits improved serviceability via "rolling upgrades". This is an important differentiator between Oracle VM Server for SPARC and traditional virtual machine environments where all virtual I/O is provided by a monolithic infrastructure that itself is a SPOF. Alternate service domains are widely used to provide resiliency in production logical domains environments. Some things are done via logical domains commands, and some are done in the guest: For example, with Oracle VM Server for SPARC we provide multiple network connections to the guest, and then configure network resiliency in the guest via IP Multi Pathing (IPMP) - essentially the same as for non-virtual systems. On the other hand, we configure virtual disk availability in the virtualization layer, and the guest sees an already-resilient disk without being aware of the details. These blogs will discuss configuration details like this. Live migration is not "high availability" in the sense of "continuous availability": If the server is down, then you don't live migrate from it! (A cluster or VM restart elsewhere would be used). However, live migration can be part of the RAS (Reliability, Availability, Serviceability) picture by improving Serviceability - you can move running domains off of a box before planned service or maintenance. The blog Best Practices - Live Migration on Oracle VM Server for SPARC discusses this. Topics Here are some of the topics that will be covered: Network availability using IP Multipathing and aggregates Disk path availability using virtual disks defined with multipath groups ("mpgroup") Disk media resiliency configuring for redundant disks that can tolerate media loss Multiple service domains - this is probably the most significant item and the one most specific to Oracle VM Server for SPARC. It is very widely deployed in production environments as the means to provide network and disk availability, but it can be confusing. Subsequent articles will describe why and how to configure multiple service domains. Note, for the sake of precision: an I/O domain is any domain that has a physical I/O resource (such as a PCIe bus root complex). A service domain is a domain providing virtual device services to other domains; it is almost always an I/O domain too (so it can have something to serve). Resources Here are some important links; we'll be drawing on their content in the next several articles: Oracle VM Server for SPARC Documentation Maximizing Application Reliability and Availability with SPARC T5 Servers whitepaper by Gary Combs Maximizing Application Reliability and Availability with the SPARC M5-32 Server whitepaper by Gary Combs Summary Oracle VM Server for SPARC offers features that can be used to provide highly-available environments. This and the following blog entries will describe how to plan and deploy them.

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