Search Results

Search found 15239 results on 610 pages for 'array population'.

Page 506/610 | < Previous Page | 502 503 504 505 506 507 508 509 510 511 512 513  | Next Page >

• RAID6 mdraid -> LVM -> EXT4 root with GRUB2?

  - by Rotonen

  2012-03-31 Debian Wheezy daily build in VirtualBox 4.1.2, 6 disk devices. My steps to reproduce so far: Setup one partition, using the entire disk, as a physical volume for RAID, per disk Setup a single RAID6 mdraid array out of all of those Use the resulting md0 as the only physical volume for the volume group Setup your logical volumes, filesystems and mount points as you wish Install your system Both / and /boot will be in this stack. I've chosen EXT4 as my filesystem for this setup. I can get as far as GRUB2 rescue console, which can see the mdraid, the volume group and the LVM logical volumes (all named appropriately on all levels) on it, but I cannot ls the filesystem contents of any of those and I cannot boot from them. As far as I can see from the documentation the version of GRUB2 shipped there should handle all of this gracefully. http://packages.debian.org/wheezy/grub-pc (1.99-17 at the time of writing.) It is loading the ext2, raid, raid6rec, dosmbr (this one is in the list of modules once per disk) and lvm modules according to the generated grub.cfg file. Also it is defining the list of modules to be loaded twice in the generated grub.cfg file and according to quick Googling around this seems to be the norm and OK for GRUB2. How to get further by getting GRUB2 to actually be able to read the content of the filesystems and boot the system? What am I wrong about in my assumptions of functionality here? EDIT (2012-04-01) My generated grub.cfg: http://pastie.org/3708436 It seems it first makes my /usr logical volume the root and that might be source of the failure? A grub-mkconfig bug? Or is it supposed to get access to stuff from /usr before / and /boot? /boot is on / for me - no separate boot logical volume.

  Read the article

• How to export SQL Server data from corrupted database (with disk write error)

  - by damitamit

  IT realised there was a disk write error on our production SQL Server 2005 and hence was causing the backups to fail. By the time they had realised this the nightly backup was old, so were not able to just restore the backup on another server. The database is still running and being used constantly. However DBCC CheckDB fails. Also the SQL Server backup task fails, Copy Database fails, Export Data Wizard fails. However it seems all the data can be read from the tables (i.e using bcp etc) Another observation I have made is that the Transaction Log is nearly double the size of the Database. (Does that mean all the changes arent being written to the MDF?) What would be the best plan of attack to get the database to a state where backups are working and the data is safe? Take the database offline and use the MDF/LDF to somehow create the database on another sql server? Export the data from the database using bcp. Create the database (use the Generate Scripts function on the corrupt db to create the schema on the new db) on another sql server and use bcp again to import the data. Some other option that is the right course of action in this situation? The IT manager says the data is safe as if the server fails, the data can be restored from the mdf/ldf. I'm not sure so insisted that we start exporting the data each night as a failsafe (using bcp for example). IT are also having issues on the hardware side of things as supposedly the disk error in on a virtualized disk and can't be rebuilt like a normal raid array (or something like that). Please excuse my use of incorrect terminology and incorrect assumptions on how Sql Server operates. I'm the application developer and have been called to help (as it seems IT know less about SQL Server than I do). Many Thanks, Amit

  Read the article

• Disadvantages of enabling 'Low Fragmentation Heap' LFH on Windows Server 2003?

  - by James Wiseman

  I've been investigating an issue with a production Classic ASP website running on IIS6 which seems indicative of memory fragmentation. One of the suggestions of how to ameliorate this came from Stackoverflow: How can I find why some classic asp pages randomly take a real long time to execute?. It suggested flipping a setting in the site's global.asa file to 'turn on' Low Fragmentation Heap (LFH). The following code (with a registered version of the accompanying DLL) did the trick. Set LFHObj=CreateObject("TURNONLFH.ObjTurnOnLFH") LFHObj.TurnOnLFH() application("TurnOnLFHResult")=CStr(LFHObj.TurnOnLFHResult) (Really the code isn't that important to the question). An author of a linked post reported a seemingly magic resolution to this issue, and, reading around a little more, I discovered that this setting is enabled by default on Windows Server 2008. So, naturally, this left me a little concerned: Why is this setting not enabled by default on 2003, or If it works in 2008 why have Microsoft not issued a patch to enable it by default on 2003? I suspect the answer to the above is the same for both (if there is one). Obviously, we're testing it in a non-production environment, and doing an array of metrics and comparisons to deem if it does help us. But aside from this I'm really just trying to understand if there's any technical reason why we should do this, or if there are any gotchas that we need to be aware of.

  Read the article

• AWS elastic load balancer basic issues

  - by Jones

  I have an array of EC2 t1.micro instances behind a load balancer and each node can manage ~100 concurrent users before it starts to get wonky. i would THINK if i have 2 such instances it would allow my network to manage 200 concurrent users... apparently not. When i really slam the server (blitz.io) with a full 275 concurrents, it behaves the same as if there is just one node. it goes from 400ms response time to 1.6 seconds (which for a single t1.micro is expected, but not 6). So the question is, am i simply not doing something right or is ELB effectively worthless? Anyone have some wisdom on this? AB logs: Loadbalancer (3x m1.medium) Document Path: /ping/index.html Document Length: 185 bytes Concurrency Level: 100 Time taken for tests: 11.668 seconds Complete requests: 50000 Failed requests: 0 Write errors: 0 Non-2xx responses: 50001 Total transferred: 19850397 bytes HTML transferred: 9250185 bytes Requests per second: 4285.10 [#/sec] (mean) Time per request: 23.337 [ms] (mean) Time per request: 0.233 [ms] (mean, across all concurrent requests) Transfer rate: 1661.35 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 1 2 4.3 2 63 Processing: 2 21 15.1 19 302 Waiting: 2 21 15.0 19 261 Total: 3 23 15.7 21 304 Single instance (1x m1.medium direct connection) Document Path: /ping/index.html Document Length: 185 bytes Concurrency Level: 100 Time taken for tests: 9.597 seconds Complete requests: 50000 Failed requests: 0 Write errors: 0 Non-2xx responses: 50001 Total transferred: 19850397 bytes HTML transferred: 9250185 bytes Requests per second: 5210.19 [#/sec] (mean) Time per request: 19.193 [ms] (mean) Time per request: 0.192 [ms] (mean, across all concurrent requests) Transfer rate: 2020.01 [Kbytes/sec] received Connection Times (ms) min mean[+/-sd] median max Connect: 1 9 128.9 3 3010 Processing: 1 10 8.7 9 141 Waiting: 1 9 8.7 8 140 Total: 2 19 129.0 12 3020

  Read the article

• How can I filter data based on items in a list?

  - by user2964366

  How can I filter entries containing any specific word in a list of words? For example, I have a list of road names in Singapore. Amoy Street, Singapore Ann Siang Hill Anson Road Arab Street Armenian Street, Singapore BBaghdad Street (Singapore) Balestier Road Banda Street Bartley Road Beach Road, Singapore Bencoolen Street Bernam Street Boat Quay Boon Tat Street Boundary Road, Singapore Bras Basah Road Bugis Street Bukit Batok Road Bukit Pasoh Road Bukit Timah Road CCantonment Road, Singapore Choa Chu Kang Road Clarke Quay Clementi Road Club Street Collyer Quay Connaught Drive Craig Road (Singapore) Cross Street and many more My spreadsheet has a large number of entries like the following, which may or may not contain road names mentioned in my list: Saw an accident at Thomson Road Found this by accident 6 vehicles crashed at Balestier Road I wanna crash now. So tired. Bus collides with bicycle at Arab Street. Accident at City Road. You can crash my house later. How do I filter to return entries that contains any road name identified in the list of names? How do I introduce an array/list of road names into Microsoft Excel and then relate it to a filter function?

  Read the article

• mkfs Operation Takes Very Long on Linux Software Raid 5

  - by Elmar Weber

  I've set-up a Linux software raid level 5 consisting of 4 * 2 TB disks. The disk array was created with a 64k stripe size and no other configuration parameters. After the initial rebuild I tried to create a filesystem and this step takes very long (about half an hour or more). I tried to create an xfs and ext3 filesystem, both took a long time, with mkfs.ext3 I observed the following behaviour, which might be helpful: writing inode tables runs fast until it reaches 1053 (~ 1 second), then it writes about 50, waits for two seconds, then the next 50 are written (according to the console display) when I try to cancel the operation with Control+C it hangs for half a minute before it is really canceled The performance of the disks individually is very good, I've run bonnie++ on each one separately with write / read values of around 95 / 110MB/s. Even when I run bonnie++ on every drive in parallel the values are only reduced by about 10 MB. So I'm excluding hardware / I/O scheduling in general as a problem source. I tried different configuration parameters for stripe_cache_size and readahead size without success, but I don't think they are that relevant for the file system creation operation. The server details: Linux server 2.6.35-27-generic #48-Ubuntu SMP x86_64 GNU/Linux mdadm - v2.6.7.1 Does anyone has a suggestion on how to further debug this?

  Read the article

• In an environment with multiple WiFi access points, do wireless clients sometimes connect to both at the same time?

  - by Bobby Burgess

  This is more of a curiosity than a problem, but in this new office I have two D-link DAP-2553's connected in a master/slave array (this just means the master keeps certain configuration options aligned with the slave). The network is set to 802.11n-only, and each AP has the same SSID and WPA2 key. The only difference is that they are on different channels (1 and 11). The WiFi network itself is working well. Users can roam around and the signal/speed is fairly consistent. However, I notice that when I look at the 802.11 client list in the web admin page for each of the 2 APs, I see that certain clients are connected to both, for extended periods of time, but I assume they are only passing data through one of them. Not every client is seen on each AP, but at any given time the same MAC address of a WiFi adapter can be associated (and remain associated) with both APs. The client list auto-refreshes every few seconds so I believe I'm looking at the most recent rather than stale information. One of the WiFi adapters that consistently associates with both APs is an Intel Centrino Wireless-N 1030 (laptop chip). Is it part of the WiFi standard that more than one association per WiFi card can be established concurrently on separate APS?

  Read the article

• How to handle sh: fetch: command not found

  - by Tyler Johnson

  Okay, I'm a noobie. I know how to build and compose a website, but I have no idea what I'm doing when it comes to servers and server commands, etc. I've recently had a problem with all of my sites on our servers going down all at once and then I have to go in and reboot the server for them to come up again. At first this was annoying, but now it is becoming agonizing as it now takes 3-4 reboots for the websites to come back up. I contacted support for my hosting, but they are not being very helpful. They just keep telling me what the issue might be and basically telling me that I'm going to have to look into it and figure it out, which really isn't possible since I know nothing. Anyway, here are the things they said were possible reasons: They said I have "strange logs" in my Apache webserver log, error: sh: fetch: command not found. My php.ini memory limit is: 256M which is very high. It should be 32M or 64M. Server is reaching Max Clients, meaning we have more than 150 visitors at a time. (They supposedly "fixed" this, but the sites/server are still going down) I have some Wordpress sites with plugins getting errors like: PHP Warning: pack(): Type H: illegal hex digit G in... PHP Fatal error: Cannot use object of type stdClass as array in... PHP Fatal error: Maximum execution time of 30 seconds exceeded in... PHP Fatal error: Call to undefined function file_exists() in... PHP Parse error: syntax error, unexpected '<' I know that's a lot, but I really am at wits end and have no idea what to do now. If anyone could maybe give me some advice or point me in the right direction I would greatly appreciate it! Thanks! Oh, and here are the specs for my server: RAM: 2048MB CPU Shares: 40 Primary Disk: 50GB Data Transfer: 75GB Port Speed: 5Mbps

  Read the article

• Can't create new Volume on Unallocated Space

  - by natediggs

  I installed Windows Server 2008 R2 on a Dell server that has one volume that is a 6 TB RAID 5 array. I created a 120GB install volume and I'm now trying to create a 5 TB data volume. For what ever reason Windows will not allow me to create a new volume out of all of the unalocated space. Windows will allow me to create a new volume out of one 2TB block of unallocated space but not the remaining 3.5 TB block. Tried to post a screen shot but I was blocked. If I right click on the 1949.85 GB block of space there is the option to create a new volume. If I click on the 3539.5 GB block of space that option is grayed out. If I go into diskpart and try to create a new partition, diskpart says that there is only 1949GBs free on the volume. I know this process works because I did the exact same thing on another server that we have that is the exact same hardware configuration on which I used the exact same Server 2008 R2 install image. Any help would be greatly appreciated. Nate

  Read the article

• ubuntu dmidecode is not functioning properly

  - by Alaa Alomari

  dmidecode is giving irrelevant and conflicted results. it shows that i have two slots while the correct is 8 (the board is Tyan S5350.) uname -a Linux synd01 3.0.0-16-server #29-Ubuntu SMP Tue Feb 14 13:08:12 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux root@synd01:/home/badmin# dmidecode -t 16 dmidecode 2.9 SMBIOS 2.33 present. Handle 0x0011, DMI type 16, 15 bytes Physical Memory Array Location: System Board Or Motherboard Use: System Memory Error Correction Type: None Maximum Capacity: 4 GB Error Information Handle: Not Provided Number Of Devices: 2 while root@synd01:/home/badmin# dmidecode -t 17 | grep Size Size: No Module Installed Size: No Module Installed Size: 1024 MB Size: 1024 MB Size: No Module Installed Size: No Module Installed Size: 1024 MB Size: 1024 MB also lshw shows: *-memory description: System Memory physical id: 11 slot: System board or motherboard size: 4GiB *-bank:0 description: DIMM DDR Synchronous 166 MHz (6.0 ns) [empty] physical id: 0 slot: J3B1 clock: 166MHz (6.0ns) *-bank:1 description: DIMM DDR Synchronous 166 MHz (6.0 ns) [empty] physical id: 1 slot: J3B3 clock: 166MHz (6.0ns) *-bank:2 description: DIMM DDR Synchronous 166 MHz (6.0 ns) physical id: 2 slot: J2B2 size: 1GiB width: 64 bits clock: 166MHz (6.0ns) *-bank:3 description: DIMM DDR Synchronous 166 MHz (6.0 ns) physical id: 3 slot: J2B4 size: 1GiB width: 64 bits clock: 166MHz (6.0ns) *-bank:4 description: DIMM DDR Synchronous 166 MHz (6.0 ns) [empty] physical id: 4 slot: J3B2 clock: 166MHz (6.0ns) *-bank:5 description: DIMM DDR Synchronous 166 MHz (6.0 ns) [empty] physical id: 5 slot: J2B1 clock: 166MHz (6.0ns) *-bank:6 description: DIMM DDR Synchronous 166 MHz (6.0 ns) physical id: 6 slot: J2B3 size: 1GiB width: 64 bits clock: 166MHz (6.0ns) *-bank:7 description: DIMM DDR Synchronous 166 MHz (6.0 ns) physical id: 7 slot: J1B1 size: 1GiB width: 64 bits clock: 166MHz (6.0ns) what might cause this conflict and how can i fix it? Thanks

  Read the article

• Windows Server 2012 Hyper-V very slow

  - by Matt Taylor

  I have been running several Hyper-V VMs on Windows Server 2008 R2 for the past couple of years and enjoying perfectly adequate performance for my testing/development/r&d environments. I'm a software developer so my hardware knowledge is basic however I built the rig using: •Gigabyte GA-X58A-UD3R Intel X58 (Socket 1366) DDR3 Motherboard •Intel Core i7 960 3.20GHz (Bloomfield) (Socket LGA1366) •24GB triple channel RAM The host OS is running on an OCZ SSD and all the VMs are running on a 2TB Marvell SATA3 RAID 0 array consisting of 2 Western Digital Caviar Black 7,200rpm drives. I have tested the speed of the 2TB drive and appear to be getting less than 3Mbs but it can adequately run a 4 VM farm including a DC, (SQL) database and IIS application servers. I recently upgraded the SSD on which the host runs to a 256GB OCZ Vertex 4 and took the opportunity to upgrade to Windows Server 2012 and installed the Hyper-V role. I tried importing one of my existing Windows Server 2008 R2 VMs (and converted it to .vhdx) plus I have tried creating a brand new Windows Server 2008 R2 VM but both are running extremely slowly and I can see nothing obvious using the host and guest Task Manager/Resource Monitor tools. In both cases the VM has 8GB RAM (fixed), 4 CPUs, fixed size HD (not expanding) and is using an external virtual network running on a separate NIC to the host. I have upgraded the BIOS to the latest available version and checked the virtualization settings. I have run out of "obvious" (to a developer) things to check/configure and my next option will be to re-install the host OS but before I do I would very much appreciate any advice from any experts out there. Thanks

  Read the article

• Disable RAID to JBOD in server IBM x3400 M2

  - by BanKtsu

  Hi I just wanna disable the default RAID in my server IBM System X3400 M2 Server(7837-24X),i have 3 disk drives SAS. I want to make them a JBOD "Just a Bunch Of Disks", because I want to install in the drive 0 CentOS, and the other two make them cache files for a squid server. I disable the RAID in the BIOS: System Settings/Adapters and UEFI drivers/LSI Logic Fusion MPT SAS Driver -PciRoot(0x0)/Pci(0x3,0X0)/Pci(0x0,0x0) LSI Logic MPT Setup Utility RAID Properties/Delete Array Later I boot the CentOS live CD and install the OS in the drive 0, and the others 2 mounted like this: *LVM Volume Groups vg_proxyserver 139508 lv_root 51200 / ext4 lv_home 84276 /home ext4 lv_swap 4032 Hard Drive sdb(/dev/sdb) free 140011 sdc(/dev/sdc) free 140011 sdd(/dev/sdd) sdd1 500 /boot ext4 sdd2 139512 vg_proxyserver physical volume(LVM) But when I restart the server give me the error: Boot failed Hard Disk 0 UEFI PXE PciRoot(0x0)/Pci(0x1,0X0)/Pci(0x0,0x0)/MAC(001A64B15130,0X0)) ........PXE-E18:Server response timeout. UEFI PXE PciRoot(0x0)/Pci(0x1,0X0)/Pci(0x0,0x0)/MAC(001A64B15132,0X0)) ........PXE-E18:Server response timeout. and the OS not start. The IBM force me to do a RAID?,why?

  Read the article

• How far should we take the N+N redundancy craziness ?

  - by Brann

  The industry standard when it comes from redundancy is quite high, to say the least. To illustrate my point, here is my current setup (I'm running a financial service). Each server has a RAID array in case something goes wrong on one hard drive .... and in case something goes wrong on the server, it's mirrored by another spare identical server ... and both server cannot go down at the same time, because I've got redundant power, and redundant network connectivity, etc ... and my hosting center itself has dual electricity connections to two different energy providers, and redundant network connectivity, and redundant toilets in case the two security guards (sorry, four) needs to use it at the same time ... and in case something goes wrong anyway (a nuclear nuke? can't think of anything else), I've got another identical hosting facility in another country with the exact same setup. Cost of reputational damage if down = very high Probability of a hardware failure with my setup : <<1% Probability of a hardware failure with a less paranoiac setup : <<1% ASWELL Probability of a software failure in our application code : 1% (if your software is never down because of bugs, then I suggest you doublecheck your reporting/monitoring system is not down. Even SQLServer - which is arguably developed and tested by clever people with a strong methodology - is sometimes down) In other words, I feel like I could host a cheap laptop in my mother's flat, and the human/software problems would still be my higher risk. Of course, there are other things to take into consideration such as : scalability data security the clients expectations that you meet the industry standard But still, hosting two servers in two different data centers (without extra spare servers, nor doubled network equipment apart from the one provided by my hosting facility) would provide me with the scalability and the physical security I need. I feel like we're reaching a point where redundancy is just a communcation tool. Honestly, what's the difference between a 99.999% uptime and a 99.9999% uptime when you know you'll be down 1% of the time because of software bugs ? How far do you push your redundancy crazyness ?

  Read the article

• Lookup Multiple Results for Multiple Criteria

  - by Matt

  I've got a list of parent SKUs for items I need to create in my inventory system. This list has been finely paired down to the 165 products we would like to carry. However, each one of these 165 SKUs has between 2 and 8 child SKUs of different colors, sizes, etc. Those are stored on a different worksheet, mixed into around 2500 items. Those are the SKUs I need to input into my inventory system. Here is what it looks like. Sheet 1 is just SKUs: A 1 2 3 4 Sheet 2 is comprised of all the child SKUs, with parent SKUs in column B. Not all parents have the same number of children: A B 1BLKM 1 1BLKL 1 1BLUM 1 2BLKM 2 2BLKL 2 2BLUM 2 2ORAM 2 3BLKM 3 3BLUM 3 I want to look up all of the child SKUs for the Parent SKU list that has been fine tuned. Parent SKU is included as a column on the child SKU worksheet. I need to lookup all matches of the Parent SKU, then continue to move down the parent SKU list until all matches for all 165 parent items have been found. It seems like every function I try can't use an Array for input. Is there a way to do this with Lookup or some combination of index, match, row, etc? Any way at all to do it without VBA? Or maybe even a VBA solution with code that I can understand, as someone who hasn't used VBA before.

  Read the article

• nginx & php-fpm and custom header

  - by nixer

  I would like to pass some custom header (ACCESS_TOKEN) from client RESTful application (JS) to application server (php-fpm). I had read that nginx should pass all http headers to php, but somehow it does not come to my php :( I can see it in firebug http://o7.no/N6DM7q but can't see it in $_SERVER variable. it just does not exist in $_SERVER array. I'm thinking that i need to pass it manually. Now my config looks like that: location @php-fpm { include /etc/nginx/fastcgi_params; fastcgi_pass unix:/tmp/php5-fpm.sock; fastcgi_param REQUEST_URI /index.php$request_uri; fastcgi_param SCRIPT_FILENAME /htdocs/index.php; fastcgi_param PATH_INFO $fastcgi_script_name; fastcgi_param DOCUMENT_ROOT /htdocs; } } and when I add new line in location definition: location @php-fpm { include /etc/nginx/fastcgi_params; ... fastcgi_param ACCESS_TOKEN $http_access_token; } } or even if i will add it into fastcgi_params file it does not help :( if I put into location part next line: fastcgi_param ACCESS_TOKEN $http_access_token; then in php it has empty value :( how I can pass custom header from client to backend (php) via nginx ?

  Read the article

• mkfs Operation Takes Very Long on Linux Software Raid 5

  - by Elmar Weber

  I've set-up a Linux software raid level 5 consisting of 4 * 2 TB disks. The disk array was created with a 64k stripe size and no other configuration parameters. After the initial rebuild I tried to create a filesystem and this step takes very long (about half an hour or more). I tried to create an xfs and ext3 filesystem, both took a long time, with mkfs.ext3 I observed the following behaviour, which might be helpful: writing inode tables runs fast until it reaches 1053 (~ 1 second), then it writes about 50, waits for two seconds, then the next 50 are written (according to the console display) when I try to cancel the operation with Control+C it hangs for half a minute before it is really canceled The performance of the disks individually is very good, I've run bonnie++ on each one separately with write / read values of around 95 / 110MB/s. Even when I run bonnie++ on every drive in parallel the values are only reduced by about 10 MB. So I'm excluding hardware / I/O scheduling in general as a problem source. I tried different configuration parameters for stripe_cache_size and readahead size without success, but I don't think they are that relevant for the file system creation operation. The server details: Linux server 2.6.35-27-generic #48-Ubuntu SMP x86_64 GNU/Linux mdadm - v2.6.7.1 Does anyone has a suggestion on how to further debug this?

  Read the article

• Scaling databases with cheap SSD hard drives

  - by Dennis Kashkin

  Hey guys! I hope that many of you are working with high traffic database-driven websites, and chances are that your main scalability issues are in the database. I noticed a couple of things lately: Most large databases require a team of DBAs in order to scale. They constantly struggle with limitations of hard drives and end up with very expensive solutions (SANs or large RAIDs, frequent maintenance windows for defragging and repartitioning, etc.) The actual annual cost of maintaining such databases is in $100K-$1M range which is too steep for me :) Finally, we got several companies like Intel, Samsung, FusionIO, etc. that just started selling extremely fast yet affordable SSD hard drives based on SLC Flash technology. These drives are 100 times faster in random read/writes than the best spinning hard drives on the market (up to 50,000 random writes per second). Their seek time is pretty much zero, so the cost of random I/O is the same as sequential I/O, which is awesome for databases. These SSD drives cost around $10-$20 per gigabyte, and they are relatively small (64GB). So, there seems to be an opportunity to avoid the HUGE costs of scaling databases the traditional way by simply building a big enough RAID 5 array of SSD drives (which would cost only a few thousand dollars). Then we don't care if the database file is fragmented, and we can afford 100 times more disk writes per second without having to spread the database across 100 spindles. . Is anybody else interested in this? I've been testing a few SSD drives and can share my results. If anybody on this site has already solved their I/O bottleneck with SSDs, I would love to hear your war stories! PS. I know that there are plenty of expensive solutions out there that help with scalability, for example the time proven RAM-based SANs. I want to be clear that even $50K is too expensive for my project. I have to find a solution that costs no more than $10K and does not take much time to implement.

  Read the article

• External Storage for 2TB of backups and 4TB of data RAID level? HW vs Software?

  - by Jerry Mayers

  I have a Mac Mini set up as a media center/file server. Currently I just have a hodgepodge mess of external drives for storage. I'm maxed out, and I have some new laptops on the way with much larger drives and I need to work out a good storage solution for backing them up, as well as storing media on the server. I need around 2 TB of storage for the time machine backups from my various systems and around 2 TB more for media. I would like to build this to handle around 6 TB total so I have some growing room. Since I'm using a Mac Mini as the server I need to use external enclosure(s) that support USB 2 or Firewire 800 (preferred) or gigabit Ethernet. Performance of the system isn't a huge concern since the majority of the access from other computers is done over 802.11N. I plan on using 2TB drives, for the final version, but initially I'll try and use my existing 2 (1TB) drives + some new 2TB drives, and swap the 1TB ones out as I fill up. As to the actual questions: Should I use hardware RAID in some enclosure? Because if the enclosure dies I have to find an identical one to get to my data right? Wouldn't a software RAID be better as I can use any method of connecting the drives to the system? Remember OS X server is my OS. What if I had to reinstall OS X, can I restore the software RAID easily? What RAID version should I use? For the 2TB used for the time machine disk I don't see why I need RAID here, just a single 2TB drive since its already the backup, but for the remaining 4TB it would be the only copy of the data so I should build some redundancy. I had a RAID 5 setup using a cheep RAID PCI card years ago running RAID 5 in a 2 TB array and when a drive died it wanted 48 hours to rebuild. Is this crazy slow for a setup of this size or is this to be expected? Any suggestions as to drive enclosures?

  Read the article

• Migrating to AWS Cloud with auto-scaling - where to put Redis and ElasticSearch?

  - by RobMasters

  I've been trying to research this topic but haven't found anywhere that recommends where to install services such as Redis and ElasticSearch when migrating to a cloud framework. I'm currently running a Symfony2 application on 2 static servers - one is running MySQL and the other is the public facing web server, which also has Redis and ElasticSearch running on it. Both of these servers are virtualised, but they're static in terms of not being able to replicate at present (various aspects are still dependent on the local filesystem). The goal is to migrate to AWS and use auto-scaling to be able to spin up and kill web servers as required, but I'm not clear on what I should put on each EC2 instance. Should they be single-responsibility only? i.e. Set up individual instances for the web server(s), Redis, and ElasticSearch and most likely an RDS instance for MySQL and only set up auto-scaling on the web server(s)? I don't foresee having to scale the ElasticSearch server anytime soon as it's only driving the search functionality, but it's possible that Redis may need to be replicated at some point - but should this be done manually? I'm not sure of how this could be done automatically as each instance needs to be configured to know about it's master/slave(s) as far as I know. I'd appreciate advice on this. One more quick question while I'm here - how would I be able to deploy code changes when there are X web servers currently active? I'm using a Capifony deployment script (Symfony2 version of Capistrano), which I think can handle multiple servers easily enough by specifying an array of :domain addresses...but how can should this be handled when the number of web servers can vary?

  Read the article

• Failing to load rootfs: Ubuntu 10 + grub2 + rootfs ext4 w/ RAID1

  - by James

  I am having problems booting a new Ubuntu 10 (server) install. My primary HD (/dev/sda) is laid out as follows: Device Boot Start End Blocks Id System /dev/sda1 * 1 18 144553+ 83 Linux <-- /BOOT /dev/sda2 19 182401 1464991447+ 5 Extended /dev/sda5 19 2207 17583111 fd Linux raid autodetect /dev/sda6 2208 11934 78132096 fd Linux raid autodetect <-- / (ROOTFS) /dev/sda7 11935 182401 1369276146 fd Linux raid autodetect The rootfs is part of a RAID1 (software) array (currently degraded): # cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md2 : active raid1 sda6[1] 78132032 blocks [2/1] [_U] The UUIDs for the partitions are as follows: # blkid /dev/sda1 /dev/sda1: UUID="b25dd301-41b9-4f4d-9b0a-0e31713dd74c" TYPE="ext2" # blkid /dev/sda6 /dev/sda6: UUID="af7b9ede-fa53-c0c1-74be-31ec752c5cd5" TYPE="linux_raid_member" # blkid /dev/md2 /dev/md2: UUID="a0602d42-6855-482f-870c-6f6ecdcdae3f" TYPE="ext4" Finally, I have my grub2 menuentry setup as follows: ### BEGIN /etc/grub.d/10_linux ### menuentry 'Ubuntu, with Linux 2.6.32-25-server' --class ubuntu --class gnu-linux --class gnu --class os { insmod ext2 insmod raid insmod mdraid set root='(hd0,1)' search --no-floppy --fs-uuid --set b25dd301-41b9-4f4d-9b0a-0e31713dd74c linux /vmlinuz-2.6.32-25-server root=UUID=a0602d42-6855-482f-870c-6f6ecdcdae3f ro nosplash noplymouth initrd /initrd.img-2.6.32-25-server } When I attempt to boot, grub loads OK, however I eventually get the following error message: Gave up waiting for root device. ALERT /dev/disk/by-uuid/a0602d42-6855-482f-870c-6f6ecdcdae3f does not exist. Dropping to a shell! If from the grub bootloader I open a grub command line, I can ls (hd0,) and it lists the correct partitions with the UUIDs as shown above - sda6 shows 'a0602d42-6855-482f-870c-6f6ecdcdae3f' (the RAID UUID). If I ls (md2)/ it properly lists all the files on the RAID1 filesystem (ext4) so it doesn't appear to be an issue accessing the raid device. Does anyone have any suggestions as to what the problem might be? I can't figure this one out.

  Read the article

• Home Server: storage virtualisation, what to choose?

  - by Huygens

  I'm looking for virtualisation solutions for storage and OS for a home server. A sort of private cloud where I manage the storage space independently of the VM one. This question focus on storage management. (I have another question related to the VM/compute instance management). Here my environement and wishes. Server: HP Proliant MicroServer with 8 GB RAM (AMD Turion dual core with AMD-V technology) with 1 250GB system disk and up to 4 HDD (2 TB) for "data" OS types: only Linux (perhaps a *BSD VM in the future) Linux distributions do not matter, I'm familiar with RHEL, Fedora, Suse, Ubuntu, but any other recommandation will be fine The 4 HDD is going to be a software RAID array, probably RAID 5. storage should be "virtualised/cloudified": easy to extend: if I add a NAS on the network, I can include the NAS space capacity within this storage space as one virtual disk. This can be a NAS, an external HDD or another server. cluster FS or S3 style space or OpenStack block storage? Whatever is easier to manage/maintain and easy to integrate/plug to VM/compute instance. I would prefer free (libre, as in a free speach) and open source tools. But it does not have to be free as in a free beer. Note: the VMs I intend to run on top of this server are one dedicated to backup, one for a "owncloud/dropbox"-like service and perhaps one for media server (hosting video and photos). I'm not sure if traditional VMs or compute instance are the most suitable for this.

  Read the article

• Recover data from Dynamic Disk (MBR) bigger than 2TB

  - by Helder

  Here is the situation: Promise Array FastTrak TX4310 with 3 disks (750 GB each) in RAID5. This comes to around 1500 GB of data. Last week I had the idea of expanding the RAID with an additional 750 GB disk. This would bring the volume to around 2250 GB. I plugged the disk and used the Webpam software to do the RAID expansion. However, I didn't count with the MBR 2TB limit, as I didn't remembered that the disk was using MBR instead of GPT and I didn't check it prior to the expansion. After a couple of days of expansion, today when I got home, the disk in Windows disk manager showed the message "Invalid disk" and when I try to activate it, it says "The operation is not allowed on the Invalid pack". From what I figured, the logical volume on the RAID expanded, and passed that info to the Windows layer and I ended up with an "larger than 2TB" MBR disk. I'm hopping that somehow I can still recover some data from this, and I was wondering if I can "rewrite" the MBR structure back to the 1500 GB partition size, so I can access the partition in Windows. Right now I'm doing an "Analyse" with TestDisk, as I hope the program will pickup the old 1500 structure and allow me to somehow revert back to it. I think that even though the Logical Drive in the RAID is bigger than the 2TB, I can somehow correct the MBR to show the 1500 GB partition again. I had a similar problem once, and I was able to recover the data using a similar method. What do you guys think? Is it a dead end? Am I totally screwed because there is the extra RAID layer that I'm not counting? Or is there other way to move with this? Thanks all!

  Read the article

• Incredble low disk performance on HP DL385 G7

  - by 3molo

  Hi, As a test of the Opteron processor family, I bought a HP DL385 G7 6128 with HP Smart Array P410i Controller - no memory. The machine has 20GB ram 2x146GB 15k rpm SAS + 2x250GB SATA2, both in Raid 1 configurations. I run Vmware ESXi 4.1. Problem: Even with one virtual machine only, tried Linux 2.6/Windows server 2008/Windows 7, the VMs' feel really sluggish. With windows 7, the vmware converter installation even timed out. Tried both SATA and SAS disks and SATA disks are nearly unsusable, while SAS disks feels extremely slow.I can't see a lot of disk activity in the infrastructure client, but I haven't been looking for causes or even tried diagnostics because I have a feeling that it's either because of the cheap raid controller - or simply because of the lack of memory for it. Despite the problems, I continued and installed a virtual machine that serves a key function, so it's not easy to take it down and run diagnostics. Would very much like to know what you guys have to say of it, is it more likely to be a problem with the controller/disks or is it low performance because of budget components? Thanks in advance,

  Read the article

• Linux Software RAID1: How to boot after (physically) removing /dev/sda? (LVM, mdadm, Grub2)

  - by flight

  A server set up with Debian 6.0/squeeze. During the squeeze installation, I configured the two 500GB SATA disks (/dev/sda and /dev/sdb) as a RAID1 (managed with mdadm). The RAID keeps a 500 GB LVM volume group (vg0). In the volume group, there's a single logical volume (lv0). vg0-lv0 is formatted with extfs3 and mounted as root partition (no dedicated /boot partition). The system boots using GRUB2. In normal use, the systems boots fine. Also, when I tried and removed the second SATA drive (/dev/sdb) after a shutdown, the system came up without problem, and after reconnecting the drive, I was able to --re-add /dev/sdb1 to the RAID array. But: After removing the first SATA drive (/dev/sda), the system won't boot any more! A GRUB welcome message shows up for a second, then the system reboots. I tried to install GRUB2 manually on /dev/sdb ("grub-install /dev/sdb"), but that doesn't help. Appearently squeeze fails to set up GRUB2 to launch from the second disk when the first disk is removed, which seems to be quite an essential feature when running this kind of Software RAID1, isn't it? At the moment, I'm lost whether this is a problem with GRUB2, with LVM or with the RAID setup. Any hints?

  Read the article

• Software RAID 1 Configuration

  - by Corve

  I have created a software RAID 1 quite some while ago and it always seemed to work for me. However I am not completely sure that I have configured everything right and do not have the experience to check so I would be very grateful for some advice or just verification that all seems right so far. I am using Linux Fedora 20 (32 bit with plans to upgrade to 64bit) The RAID 1 should consist of two 1TB SATA hard drives. This is the output of mdadm --detail /dev/md0 /dev/md0: Version : 1.2 Creation Time : Sun Jan 29 11:25:18 2012 Raid Level : raid1 Array Size : 976761424 (931.51 GiB 1000.20 GB) Used Dev Size : 976761424 (931.51 GiB 1000.20 GB) Raid Devices : 2 Total Devices : 1 Persistence : Superblock is persistent Update Time : Sat Jun 7 10:38:09 2014 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 Name : argo:0 (local to host argo) UUID : 1596d0a1:5806e590:c56d0b27:765e3220 Events : 996387 Number Major Minor RaidDevice State 0 0 0 0 removed 1 8 0 1 active sync /dev/sda The RAID is mounted successfully: friedrich@argo:~ ? sudo mount -l | grep md0 /dev/md0 on /mnt/raid type ext4 (rw,relatime,data=ordered) Basically my question are: Why do I only have 1 active device? What does the State removed at bottom mean? Also I noticed some strange error messages that I see on the console on system start and shutdown and always repeating in the background when I switch with Ctrl + Alt + F2: ... ata2: irq_stat 0x00000040 connection status changed ata2: SError: { CommWake DevExch } ata2: COMRESET failed (errno=-32) ata2: exception Emask 0x10 SAct 0x0 SErr 0x4040000 action 0xe frozen ata2: irq_stat 0x00000040 connection status changed ata2: SError: { CommWake DevExch } ata2: exception Emask 0x10 SAct 0x0 SErr 0x4040000 action 0xe frozen ... Are these errors related to the RAID? Something seems wrong with the SATA devices.. All together the system works (I can read and write to the mounted raid) but I always had these strange errors on startup shutdown (probably always in the background). Thx for your help

  Read the article

< Previous Page | 502 503 504 505 506 507 508 509 510 511 512 513  | Next Page >