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• Windows 2003 Storage Server Hanging on Large File Transfers

  - by user25272

  In one of our offices we have a Dell PowerVault 745N NAS device which acts as the main file server. Its running 32bit Windows 2003 Storage Server SP2 with 3GB RAM. The server holds around 60 users HOME folders, which are mapped via AD. The office clients are a mix of XP SP3, Vista and Windows 7. Occasionally the server will completely hang when transferring large files. When the hang happens the console becomes unresponsive with only the mouse active and blank wallpaper. Sometimes stopping the copy frees the server, sometimes not. The hanging can last around 20 minutes. During this time other servers also become unresponsive with blank wallpaper at the console. If you do manage to get onto another server the taskbar and run commands are unresponsive. This also transcends to the client computers sometimes with explorer crashing. I'm guessing this is due to the HOME folder mapping. Eventually the NAS server with free up and everything will be back to normal. The server is configured as follows: PERC 4/DC DATA 2 - 12 SCSI HDD - RAID5 SHADOWCOPY 2 SCSI HDD - RAID1 CERC SATA DATA 11 4 SATA HDD - RAID5 OS 4 SATA HDD - RAID5 All the drivers and firmware is up to date. I've been through all the diagnostics with Dell and the hardware has come up clean including full HDD tests on the arrays. The server has NOD32 installed as the AV, but the hanging happens when it is uninstalled. There are no errors in the event log when this happens and we don't have any errors logged on any of our ProCurve switches. DNS is fine on the domain and AD from what I can tell is running happily. There are no DFS or NFS shares setup either. All the shares are standard Windows. I've unchecked the allow the computer to turn off this device to save power box under Power Management on the NIC. "Set Link Speed and Duplex to Auto-negotiate 1000 " Increased Receive Descriptors buffer from 256 to 352 (reserves more CPU resource for handling data) I've run network traces using network monitor and have found the following: 417 8.078125 {SMB:192, NbtSS:25, TCP:24, IPv4:23} 192.168.2.244 192.168.5.35 SMB SMB:R; Nt Create Andx - NT Status: System - Error, Code = (52) STATUS_OBJECT_NAME_NOT_FOUND I've tried different cabling; NICs and switch ports all with the same result. Transferring files from other servers on the domain is fine. All I haven't done is run CHKDSK on the drives to look for any file system errors. On the Vista clients I have also run netsh interface tcp set global autotuning=disabled with no result. Could it be that the server has a faulty drive or that the I/O is too much for it to handle? Any ideas why would the hang cause issues with the other servers on the LAN? Many Thanks.

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• Advice? SSO in N-tiered SOA with mixture of REST and SOAP services

  - by Tyler

  Hi gang, We are moving to SSO in our N-tiered SOA applications. If all the services were SOAP, I'd be ok with just the WS-Security, WS-Trust, WS-Federation set of protocols. My problem is that many of the services are RESTful (ironic) and those protocols do not address REST services. What is your advice for SSO protecting the REST services in an N-tiered SOA architecture with the following requirements: ideally claims-based identity information available to the REST services original user (eg. bootstrap) information must flow through the tiers so that each service can "ActAs" or "OnBehalfOf" the user support sequences like: WebApp -- REST Svc -- SOAP Svc WebApp -- REST Svc1 -- REST Svc2 WebApp -- SOAP Svc -- REST Svc WebApp -- SOAP Svc1 -- SOAP Svc2 support SSO (and SSOff) service/web app platforms: ASP.Net and WCF Java end-user client platforms: .Net (WSE 3.0 and WCF) flash 10 java javascript and AJAX Normally I'm good at climbing / bashing my way through walls, but this one's knocked me flat. Hopefully with your help, we can get over this one. Thanks, Tyler

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• 404 redirect with cloud storage

  - by Jeremy DeGroot

  I'm hoping to reach someone with some experience using a service like Amazon's S3 with this question. On my site we have a dedicated image server. And on this server, we have an automatic 404 redirect through Apapche so that, if a user tries to access an image that doesn't exist, they'll see a snazzy "Image Not Available" image. We're looking to move the hosting of these images to a cloud storage solution (S3 or Rackspace's CloudFiles), and I'm wondering if anyone's had any success replicating this behavior on a cloud storage service and if so how they did it.

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• MySQL index cardinality - performance vs storage efficiency

  - by Sean

  Say you have a MySQL 5.0 MyISAM table with 100 million rows, with one index (other than primary key) on two integer columns. From my admittedly poor understanding of B-tree structure, I believe that a lower cardinality means the storage efficiency of the index is better, because there are less parent nodes. Whereas a higher cardinality means less efficient storage, but faster read performance, because it has to navigate through less branches to get to whatever data it is looking for to narrow down the rows for the query. (Note - by "low" vs "high", I don't mean e.g. 1 million vs 99 million for a 100 million row table. I mean more like 90 million vs 95 million) Is my understanding correct? Related question - How does cardinality affect write performance?

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• WPF: isolated storage file path too long

  - by user342961

  Hi, I'm deploying my WPF app with ClickOnce. When developing locally in Visual Studio, I store files in the isolated storage by calling IsolatedStorageFile.GetUserStoreForDomain(). This works just fine and the generated path is C:\Users\Frederik\AppData\Local\IsolatedStorage\phqduaro.crw\hux3pljr.cnx\StrongName.kkulk3wafjkvclxpwvxmpvslqqwckuh0\Publisher.ui0lr4tpq53mz2v2c0uqx21xze0w22gq\Files\FilerefData\-581750116 (189 chars) But when I deploy my app with ClickOnce, the generated path becomes too long, resulting in a DirectoryNotFoundException when creating the isolated storage directory. The generated path with ClickOnce is: C:\Users\Frederik\AppData\Local\Apps\2.0\Data\OQ0LNXJT.R5V\8539ABHC.ODN\exqu..tion_e07264ceafd7486e_0001.0000_b8f01b38216164a0\Data\StrongName.wy0cojdd3mpvq45404l3gxdklugoanvi\Publisher.ui0lr4tpq53mz2v2c0uqx21xze0w22gq\Files\FilerefData\-581750116 (247 chars) When I browse the folders all but the last directory of the path exists. Then when trying to create a folder at this location windows tells me I can't create a directory because the resulting path name will be too long. How can I shorten the path generated by the IsolatedStorage?

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• Getting USB Storage Device Instance ID (unique ID) programmatically

  - by Navaneeth

  Whenever user plug a USB mass storage device, how to get the Device Instance ID (unique ID) of that particular device programmatically?

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• Get storage engine in MySql

  - by Marco

  Hi, how do i get the storage engine used by a specific database in MySql? Thanks

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• Zend_Auth / Zend_Session error and storing objects in Auth Storage

  - by Martin

  Hi All, I have been having a bit of a problem with Zend_Auth and keep getting an error within my Acl. Within my Login Controller I setup my Zend_Auth storage as follows $auth = Zend_Auth::getInstance(); $result = $auth->authenticate($adapter); if ($result->isValid()) { $userId = $adapter->getResultRowObject(array('user_id'), null)->user_id; $user = new User_Model_User; $users = new User_Model_UserMapper; $users->find($userId, $user); $auth->getStorage()->write( $user ); } This seems to work well and I am able to use the object stored in the Zend_Auth storage within View Helpers without any problems. The problem that I seem to be having is when I try to use this within my Acl, below is a snippet from my Acl, as soon as it gets to the if($auth->hasIdentity()) { line I get the exception detailed further down. The $user->getUserLevel() is a methord within the User Model that allows me to convert the user_level_id that is stored in the database to a meaning full name. I am assuming that the auto loader sees these kind of methords and tries to load all the classes that would be required. When looking at the exception it appears to be struggling to find the class as it is stored in a module, I have the Auto Loader Name Space setup in my application.ini. Could anyone help with resolving this? class App_Controller_Plugin_Acl extends Zend_Controller_Plugin_Abstract { protected $_roleName; public function __construct() { $auth = Zend_Auth::getInstance(); if($auth->hasIdentity()) { $user = $auth->getIdentity(); $this->_roleName = strtolower($user->getUserLevel()); } else { $this->_roleName = 'guest'; } } } Fatal error: Uncaught exception 'Zend_Session_Exception' with message 'Zend_Session::start() - \Web\library\Zend\Loader.php(Line:146): Error #2 include_once() [&lt;a href='function.include'&gt;function.include&lt;/a&gt;]: Failed opening 'Menu\Model\UserLevel.php' for inclusion (include_path='\Web\application/../library;\Web\library;.;C:\php5\pear') Array' in \Web\library\Zend\Session.php:493 Stack trace: #0 \Web\library\Zend\Session\Namespace.php(143): Zend_Session::start(true) #1 \Web\library\Zend\Auth\Storage\Session.php(87): Zend_Session_Namespace-&gt;__construct('Zend_Auth') #2 \Web\library\Zend\Auth.php(91): Zend_Auth_Storage_Session-&gt;__construct() #3 \Web\library\Zend\A in \Web\library\Zend\Session.php on line 493 Thanks, Martin

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• Convert ASP.NET membership system to secure password storage

  - by wrburgess

  I have a potential client that set up their website and membership system in ASP.NET 3.5. When their developer set up the system, it seems he turned off the security/hashing aspect of password storage and everything is stored in the clear. Is there a process to reinstall/change the secure password storage of ASP.NET membership without changing all of the passwords in the database? The client is worried that they'll lose their customers if they all have to go through a massive password change. I've always installed with security on by default, thus I don't know the effect of a switchover. Is there a way to convert the entire system to a secure password system without major effects on the users?

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• Silverlight Isolated Storage and loading big files

  - by Thomas Joulin

  In a Windows Phone 7 application, I would like to query a big XML file (list of cities) stored using Isolated Storage. If I do that this way, will the file be loaded to memory ( 5 mo) ? If so, what other solution do I have? Edit: More details. I want to use AutoCompleteBox (http://www.jeff.wilcox.name/2008/10/introducing-autocompletebox/), but instead of using a web service (this is fixed data, no need to be online), I want to query a file/database/isolated storage... I have a fixed list of cities. I said in the comments it's 40k, but it finally seems closer to 1k rows.

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• Moving webshop storage to NoSQL solution

  - by mare

  If you had a webshop solution based on SQL Server relational DB what would be the reasons, if any, to move to NoSQL storage ? Does it even make sense to migrate datastores that rely on relations heavily to NoSQL? If starting from scratch, would you choose NoSQL solution over relational one for a webshop project, which will, after a while, again end up with a bunch of tables like Articles, Classifications, TaxRates, Pricelists etc. and a magnitude of relations between them? What's the support like in .NET (4.0) for MongoDB or MongoDB's support for .NET 4.0? Can I count on rich code generation tools similar to EF wizard, L2SQL wizard etc. for MongoDB? Because as what I have read so far, NoSQL's are mostly suited for document storage, simpler object models. Your answer to this question will help me make the right infrastructure design decisions.

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• MySQL storage engine dilemma

  - by burntblark

  There are two MySQL database features that I want to use in my application. The first is FULL-TEXT-SEARCH and TRANSACTIONS. Now, the dilemma here is that I cannot get this feature in one storage engine. It's either I use MyIsam (which has the FULL-TEXT-SEARCH feature) or I use InnoDB (which supports the TRANSACTION feature). I can't have both. My question is, is there anyway I can have both features in my application before I am forced to make a choice between the two storage engines.

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• Rapid Repository – Silverlight Development

  - by SeanMcAlinden

  Hi All, One of the questions I was recently asked was whether the Rapid Repository would work for normal Silverlight development as well as for the Windows 7 Phone. I can confirm that the current code in the trunk will definitely work for both the Windows 7 Phone and normal Silverlight development. I haven’t tested V.1.0 for compatibility but V2.0 which will be released fairly soon will work absolutely fine.   Kind Regards, Sean McAlinden.

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• Windows 7 Phone Database Rapid Repository – V2.0 Beta Released

  - by SeanMcAlinden

  Hi All, A V2.0 beta has been released for the Windows 7 Phone database Rapid Repository, this can be downloaded at the following: http://rapidrepository.codeplex.com/ Along with the new View feature which greatly enhances querying and performance, various bugs have been fixed including a more serious bug with the caching that caused the GetAll() method to sometimes return inconsistent results (I’m a little bit embarrased by this bug). If you are currently using V1.0 in development, I would recommend swapping in the beta immediately. A full release will be available very shortly, I just need a few more days of testing and some input from other users/testers.   *Breaking Changes* The only real change is the RapidContext has moved under the main RapidRepository namespace. Various internal methods have been actually made ‘internal’ and replaced with a more friendly API (I imagine not many users will notice this change). Hope you like it Kind Regards, Sean McAlinden

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• Windows 7 Phone Database – Querying with Views and Filters

  - by SeanMcAlinden

  I’ve just added a feature to Rapid Repository to greatly improve how the Windows 7 Phone Database is queried for performance (This is in the trunk not in Release V1.0). The main concept behind it is to create a View Model class which would have only the minimum data you need for a page. This View Model is then stored and retrieved rather than the whole list of entities. Another feature of the views is that they can be pre-filtered to even further improve performance when querying. You can download the source from the Microsoft Codeplex site http://rapidrepository.codeplex.com/. Setting up a view Lets say you have an entity that stores lots of data about a game result for example: GameScore entity public class GameScore : IRapidEntity {     public Guid Id { get; set; }     public string GamerId {get;set;}     public string Name { get; set; }     public Double Score { get; set; }     public Byte[] ThumbnailAvatar { get; set; }     public DateTime DateAdded { get; set; } }   On your page you want to display a list of scores but you only want to display the score and the date added, you create a View Model for displaying just those properties. GameScoreView public class GameScoreView : IRapidView {     public Guid Id { get; set; }     public Double Score { get; set; }     public DateTime DateAdded { get; set; } }   Now you have the view model, the first thing to do is set up the view at application start up. This is done using the following syntax. View Setup public MainPage() {     RapidRepository<GameScore>.AddView<GameScoreView>(x => new GameScoreView { DateAdded = x.DateAdded, Score = x.Score }); } As you can see, using a little bit of lambda syntax, you put in the code for constructing a single view, this is used internally for mapping an entity to a view. *Note* you do not need to map the Id property, this is done automatically, a view model id will always be the same as it’s corresponding entity.   Adding Filters One of the cool features of the view is that you can add filters to limit the amount of data stored in the view, this will dramatically improve performance. You can add multiple filters using the fluent syntax if required. In this example, lets say that you will only ever show the scores for the last 10 days, you could add a filter like the following: Add single filter public MainPage() {     RapidRepository<GameScore>.AddView<GameScoreView>(x => new GameScoreView { DateAdded = x.DateAdded, Score = x.Score })         .AddFilter(x => x.DateAdded > DateTime.Now.AddDays(-10)); } If you wanted to further limit the data, you could also say only scores above 100: Add multiple filters public MainPage() {     RapidRepository<GameScore>.AddView<GameScoreView>(x => new GameScoreView { DateAdded = x.DateAdded, Score = x.Score })         .AddFilter(x => x.DateAdded > DateTime.Now.AddDays(-10))         .AddFilter(x => x.Score > 100); }   Querying the view model So the important part is how to query the data. This is done using the repository, there is a method called Query which accepts the type of view as a generic parameter (you can have multiple View Model types per entity type) You can either use the result of the query method directly or perform further querying on the result is required. Querying the View public void DisplayScores() {     RapidRepository<GameScore> repository = new RapidRepository<GameScore>();     List<GameScoreView> scores = repository.Query<GameScoreView>();       // display logic } Further Filtering public void TodaysScores() {     RapidRepository<GameScore> repository = new RapidRepository<GameScore>();     List<GameScoreView> todaysScores = repository.Query<GameScoreView>().Where(x => x.DateAdded > DateTime.Now.AddDays(-1)).ToList();       // display logic }   Retrieving the actual entity Retrieving the actual entity can be done easily by using the GetById method on the repository. Say for example you allow the user to click on a specific score to get further information, you can use the Id populated in the returned View Model GameScoreView and use it directly on the repository to retrieve the full entity. Get Full Entity public void GetFullEntity(Guid gameScoreViewId) {     RapidRepository<GameScore> repository = new RapidRepository<GameScore>();     GameScore fullEntity = repository.GetById(gameScoreViewId);       // display logic } Synchronising The View If you are upgrading from Rapid Repository V1.0 and are likely to have data in the repository already, you will need to perform a synchronisation to ensure the views and entities are fully in sync. You can either do this as a one off during the application upgrade or if you are a little more cautious, you could run this at each application start up. Synchronise the view public void MyUpgradeTasks() {     RapidRepository<GameScore>.SynchroniseView<GameScoreView>(); } It’s worth noting that in normal operation, the view keeps itself in sync with the entities so this is only really required if you are upgrading from V1.0 to V2.0 when it gets released shortly.   Summary I really hope you like this feature, it will be great for performance and I believe supports good practice by promoting the use of View Models for specific pages. I’m hoping to produce a beta for this over the next few days, I just want to add some more tests and hopefully iron out any bugs. I would really appreciate any thoughts on this feature and would really love to know of any bugs you find. You can download the source from the following : http://rapidrepository.codeplex.com/ Kind Regards, Sean McAlinden.

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• SQLAuthority News – SQL Server Technical Article – The Data Loading Performance Guide

  - by pinaldave

  The white paper describes load strategies for achieving high-speed data modifications of a Microsoft SQL Server database. “Bulk Load Methods” and “Other Minimally Logged and Metadata Operations” provide an overview of two key and interrelated concepts for high-speed data loading: bulk loading and metadata operations. After this background knowledge, white paper describe how these methods can be [...]

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• Trace Flag 610 – When should you use it?

  - by simonsabin

  Thanks to Marcel van der Holst for providing this great information on the use of Trace Flag 610. This trace flag can be used to have minimal logging into a b tree (i.e. clustered table or an index on a heap) that already has data. It is a trace flag because in testing they found some scenarios where it didn’t perform as well. Marcel explains why below. “ TF610 can be used to get minimal logging in a non-empty B-Tree. The idea is that when you insert a large amount of data, you don't want to...(read more)

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• Access and Manage Your Ubuntu One Account in Chrome and Iron

  - by Asian Angel

  Do you have an Ubuntu One account that you access across different operating systems? Whether you are using Ubuntu, a different flavor of Linux, Windows, or Mac the Ubuntu One web app makes it easy to access and manage your Ubuntu One account in just moments. The Ubuntu One web app will definitely be useful if you find yourself away from your favorite Ubuntu computer but need to get important files uploaded to your account. Ubuntu One [Chrome Web Store] Latest Features How-To Geek ETC Learn To Adjust Contrast Like a Pro in Photoshop, GIMP, and Paint.NET Have You Ever Wondered How Your Operating System Got Its Name? Should You Delete Windows 7 Service Pack Backup Files to Save Space? What Can Super Mario Teach Us About Graphics Technology? Windows 7 Service Pack 1 is Released: But Should You Install It? How To Make Hundreds of Complex Photo Edits in Seconds With Photoshop Actions Access and Manage Your Ubuntu One Account in Chrome and Iron Mouse Over YouTube Previews YouTube Videos in Chrome Watch a Machine Get Upgraded from MS-DOS to Windows 7 [Video] Bring the Whole Ubuntu Gang Home to Your Desktop with this Mascots Wallpaper Hack Apart a Highlighter to Create UV-Reactive Flowers [Science] Add a “Textmate Style” Lightweight Text Editor with Dropbox Syncing to Chrome and Iron

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• Back Up to Tape the Way You Shop For Groceries

  - by rickramsey

  Imagine if this was how you shopped for groceries: From the end of the aisle sprint to the point where you reach the ketchup. Pull a bottle from the shelf and yell at the top of your lungs, “Got it!” Sprint back to the end of the aisle. Start again and sprint down the same aisle to the mustard, pull a bottle from the shelf and again yell for the whole store to hear, “Got it!” Sprint back to the end of the aisle. Repeat this procedure for every item you need in the aisle. Proceed to the next aisle and follow the same steps for the list of items you need from that aisle. Sounds ridiculous, doesn’t it? Not only is it horribly inefficient, it’s exhausting and can lead to wear out failures on your grocery cart, or worse, yourself. This is essentially how NetApp and some other applications write NDMP backups to tape. In the analogy, the ketchup and mustard are the files to be written, yelling “Got it!” is the equivalent of a sync mark at the end of a file, and the sprint back to the end of an aisle is the process most commonly called a “backhitch” where the drive has to back up on a tape to start writing again. Writing to tape in this way results in very slow tape drive performance and imposes unnecessary wear on the tape drive and the media, especially when writing small files. The good news is not all tape drives behave this way when writing small files. Unlike midrange LTO drives, Oracle’s StorageTek T10000D tape drive is designed to handle this scenario efficiently. The difference between the two drive types is that the T10000D drive gives you the ability to write files in a NetApp NDMP backup environment the way you would normally shop for groceries. With grocery shopping, you essentially stream through aisles picking up items as you go, and then after checking out, yell, “Got it!”, though you might do that last step silently. With the T10000D, it has a feature called the Tape Application Accelerator, which prevents the drive from having to stop after each file is written to notify NetApp or another application that the write was successful. When enabled in the T10000D tape drive, Tape Application Accelerator causes the tape drive to respond to tape mark and file sync commands differently than when disabled: A tape mark received by the tape drive is treated as a buffered tape mark. A file sync received by the tape drive is treated as a no op command. Since buffered tape marks and no op commands do not cause the tape drive to empty the contents of its buffer to tape and backhitch, the data is written to tape in significantly less time. Oracle has emulated NetApp environments with a number of different file sizes and found the following when comparing the T10000D with the Tape Application Accelerator enabled versus LTO6 tape drives. Notice how the T10000D is not only monumentally faster, but also remarkably consistent? In addition, the writing of the 50 GB of files is done without a single backhitch. The LTO6 drive, meanwhile, will perform as many as 3,800 backhitches! At the end of writing the entire set of files, the T10000D tape drive reports back to the application, in this case NetApp, that the write was successful via a tape mark. So if the Tape Application Accelerator dramatically improves performance and reliability, why wouldn’t you always have it enabled? The reason is because tape drive buffers are meant to be just temporary data repositories so in the event of a power loss, there could be data loss in certain environments for the files that resided in the buffer. Fortunately, we do have best practices depending on your environment to avoid this from happening. I highly recommend reading Maximizing Tape Performance with StorageTek T10000 Tape Drives (pdf) to decide which best practice is right for you. The white paper also digs deeper into the benefits of the Tape Application Accelerator. The white paper is free, and after downloading it you can decide for yourself whether you want to yell “Got it!” out loud or just silently to yourself. Customer Advisory Panel One final link: Oracle has started up a Customer Advisory Panel program to collect feedback from customers on their current experiences with Oracle products, as well as desires for future product development. If you would like to participate in the program, go to this link at oracle.com. photo taken on Idaho's Sacajewea Historic Biway by Rick Ramsey - Brian Zents Follow OTN on Blog | Facebook | Twitter | YouTube

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• Don’t Miss The Top Exastack ISV Headlines – Week Of June 5

  - by Roxana Babiciu

  Kerridge achieves Oracle Exadata Optimized status with K8, an ERP Solution for distribution, merchant and wholesale/retail sectors. The online transactional processing saw a 12x increase in the volume throughput from previous benchmarks – Watch video. Accenture achieves Oracle Exalogic Optimized status with AFPO, a unique accelerator for customer-facing solutions. Over 125 clients cut their implementation costs by up to thirty percent – Read more.

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• Don’t Miss The Top Exastack ISV Headlines – Week Of May 26

  - by Roxana Babiciu

  Calypso Technology announced that Calypso version 14 has achieved Oracle Exadata Optimized status through OPN. In simulations of data-intensive straight through-processing tasks, Calypso achieved performance gains of up to 500% using Exadata hardware – Read more Infosys achieves Oracle SuperCluster Optimized status with Finacle, a core banking solution. Finacle can process 6x the volume of transactions currently processed by the entire US banking system – Read more

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• Don’t Miss The Top Exastack ISV Headlines – Week Of June 5

  - by Roxana Babiciu

  Smartsoft's OCEAN Payment Processing Solution achieves Oracle Exadata Optimized status. "Performance is the most important issue for our success in the market and running OCEAN on the Oracle Exadata Database Machine provides customers with extreme performance.” – Learn more Banking solution FORBIS Ltd’s FORPOST achieves Oracle Exadata, Exalogic and SuperCluster Ready Status. “We are glad to offer our current and future customers the newest features provided by Oracle Engineered Systems to achieve maximum reliability and speed operation.” – Learn more

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• Why is my external USB hard drive sometimes completely inaccessible?

  - by Eliah Kagan

  I have an external USB hard drive, consisting of an 1 TB SATA drive in a Rosewill RX35-AT-SU SLV Aluminum 3.5" Silver USB 2.0 External Enclosure, plugged into my SONY VAIO VGN-NS310F laptop. It is plugged directly into the computer (not through a hub). The drive inside the enclosure is a 7200 rpm Western Digital, but I don't remember the exact model. I can remove the drive from the enclosure (again), if people think it's necessary to know that detail. The drive is formatted ext4. I mount it dynamically with udisks on my Lubuntu 11.10 system, usually automatically via PCManFM. (I have had Lubuntu 12.04 on this machine, and experienced all this same behavior with that too.) Every once in a while--once or twice a day--it becomes inaccessible, and difficult to unmount. Attempting to unmount it with sudo umount ... gives an error message saying the drive is in use and suggesting fuser and lsof to find out what is using it. Killing processes found to be using the drive with fuser and lsof is sometimes sufficient to let me unmount it, but usually isn't. Once the drive is unmounted or the machine is rebooted, the drive will not mount. Plugging in the drive and turning it on registers nothing on the computer. dmesg is unchanged. The drive's access light usually blinks vigorously, as though the drive is being accessed constantly. Then eventually, after I keep the drive off for a while (half an hour), I am able to mount it again. While the drive doesn't work on this machine for a while, it will work immediately on another machine running the same version of Ubuntu. Sometimes bringing it back over from the other machine seems to "fix" it. Sometimes it doesn't. The drive doesn't always stop being accessible while mounted, before becoming unmountable. Sometimes it works fine, I turn off the computer, I turn the computer back on, and I cannot mount the drive. Currently this is the only drive with which I have this problem, but I've had problems that I think are the same as this, with different drives, on different Ubuntu machines. This laptop has another external USB drive plugged into it regularly, which doesn't have this problem. Unplugging that drive before plugging in the "problem" drive doesn't fix the problem. I've opened the drive up and made sure the connections were tight in the past, and that didn't seem to help (any more than waiting the same amount of time that it took to open and close the drive, before attempting to remount it). Does anyone have any ideas about what could be causing this, what troubleshooting steps I should perform, and/or how I could fix this problem altogether? Update: I tried replacing the USB data cable (from the enclosure to the laptop), as Merlin suggested. I should've tried that long ago, since it fits the symptoms perfectly (the drive works on another machine, which would make sense because the cable would be bent at a different angle, possibly completing a circuit of frayed wires). Unfortunately, though, this did not help--I have the same problem with the new cable. I'll try to provide additional detailed information about the drive inside the enclosure, next time I'm able to get the drive working. (At the moment I don't have another machine available to attach it.) Major Update (28 June 2012) The drive seems to have deteriorated considerably. I think this is so, because I've attached it to another machine and gotten lots of errors about invalid characters, when copying files from it. I am less interested in recovering data from the drive than I am in figuring out what is wrong with it. I specifically want to figure out if the problem is the drive or the enclosure. Now, when I plug the drive into the original machine where I was having the problems, it still doesn't appear (including with sudo fdisk -l), but it is recognized by the kernel and messages are added to dmesg. Most of the message consist of errors like this, repeated many times: [ 7.707593] sd 5:0:0:0: [sdc] Unhandled sense code [ 7.707599] sd 5:0:0:0: [sdc] Result: hostbyte=invalid driverbyte=DRIVER_SENSE [ 7.707606] sd 5:0:0:0: [sdc] Sense Key : Medium Error [current] [ 7.707614] sd 5:0:0:0: [sdc] Add. Sense: Unrecovered read error [ 7.707621] sd 5:0:0:0: [sdc] CDB: Read(10): 28 00 00 00 00 00 00 00 08 00 [ 7.707636] end_request: critical target error, dev sdc, sector 0 [ 7.707641] Buffer I/O error on device sdc, logical block 0 Here are all the lines from dmesg starting with when the drive is recognized. Please note that: I'm back to running Lubuntu 12.04 on this machine (and perhaps that's a factor in better error messages). Now that the drive has been plugged into another machine and back into this one, and also now that this machine is back to running 12.04, the drive's access light doesn't blink as I had described. Looking at the drive, it would appear as though it is working normally, with low or no access. This behavior (the errors) occurs when rebooting the machine with the drive plugged in, and also when manually plugging in the drive. A few of the messages are about /dev/sdb. That drive is working fine. The bad drive is /dev/sdc. I just didn't want to edit anything out from the middle.

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• unable to format usb 1204 [daemon inhibited ]

  - by santosamaru

  i try to format my usb 1st time its work all data gone but i can't save any file at this usb . then i try to check is it working or broken here the report santos@santos:~$ sudo badblocks -v /dev/sdb [sudo] password for santos: Sorry, try again. [sudo] password for santos: Checking blocks 0 to 7824383 Checking for bad blocks (read-only test): 0.00% done, 0:00 elapsed. (0/0/0 errdone Pass completed, 0 bad blocks found. (0/0/0 errors) santos@santos:~$ sudo badblocks -v -w /dev/sdb [sudo] password for santos: Sorry, try again. [sudo] password for santos: /dev/sdb is apparently in use by the system; it's not safe to run badblocks! santos@santos:~$ how to format and fix this issues? i have read this link Formatting Pen Drive causes 'Daemon Is Inhibited' Error and it said like this when i try to move any items from desktop " the destination is read only also in this case i use google and find this http://ubuntuforums.org/showthread.php?t=1955353 article as same its not helped following user13509 suggestion ..

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• What is the best strategy for transforming unicode strings into filenames?

  - by David Cowden

  I have a bunch (thousands) of resources in an RDF/XML file. I am writing a certain subset of the resources to files -- one file for each, and I'm using the resource's title property as the file name. However, the titles are every day article, website, and blog post titles, so they contain characters unsafe for a URI (the necessary step for constructing a valid file path). I know of the Jersey UriBuilder but I can't quite get it to work for my needs as I detailed in a different question on SO. Some possibilities I have considered are: Since each resource should also have an associated URL, I could try to use the name of the file on the server. The down side of this is sometimes people don't name their content logically and I think the title of an article better reflects the content that will be in each text file. Construct a white list of valid characters and parse the string myself defining substitutions for unsafe characters. The downside of this is the result could be just as unreadable as the former solution because presumably the content creators went through a similar process when placing the files on their server. Choose a more generic naming scheme, place the title in the text file along with the other attributes, and tell my boss to live with it. So my question here is, what methods work well for dealing with a scenario where you need to construct file names out of strings with potentially unsafe characters? Is there a solution that better fills out my constraints?

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