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• Reconfigure RAID on Dell PowerEdge T710

  - by Stefano Borini

  I have a Dell PowerEdge T710 under my feet at this very moment, with RedHat Enterprise Server 5.3. I have 6 1TB disks and two 500GB. parted reports two devices, one 500 GB and the other 4 TB. So I assume the RAID has been setup as mirror for two disks, and I assume as RAID 5 the remaining ones. I say "I assume" because it does not make sense. Having 6 disks in RAID 5, I should obtain a total space of 5 TB, not 4TB. It's not even RAID 10: I would end up with a 3 TB unit. How can I check and eventually modify the RAID array definition? In the Fujitsu Siemens I played with some time ago, at boot I had the chance to enter the controller BIOS, but here I don't see a clear way to perform this operation.

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• Creating a JSONP Formatter for ASP.NET Web API

  - by Rick Strahl

  Out of the box ASP.NET WebAPI does not include a JSONP formatter, but it's actually very easy to create a custom formatter that implements this functionality. JSONP is one way to allow Browser based JavaScript client applications to bypass cross-site scripting limitations and serve data from the non-current Web server. AJAX in Web Applications uses the XmlHttp object which by default doesn't allow access to remote domains. There are number of ways around this limitation <script> tag loading and JSONP is one of the easiest and semi-official ways that you can do this. JSONP works by combining JSON data and wrapping it into a function call that is executed when the JSONP data is returned. If you use a tool like jQUery it's extremely easy to access JSONP content. Imagine that you have a URL like this: http://RemoteDomain/aspnetWebApi/albums which on an HTTP GET serves some data - in this case an array of record albums. This URL is always directly accessible from an AJAX request if the URL is on the same domain as the parent request. However, if that URL lives on a separate server it won't be easily accessible to an AJAX request. Now, if  the server can serve up JSONP this data can be accessed cross domain from a browser client. Using jQuery it's really easy to retrieve the same data with JSONP:function getAlbums() { $.getJSON("http://remotedomain/aspnetWebApi/albums?callback=?",null, function (albums) { alert(albums.length); }); } The resulting callback the same as if the call was to a local server when the data is returned. jQuery deserializes the data and feeds it into the method. Here the array is received and I simply echo back the number of items returned. From here your app is ready to use the data as needed. This all works fine - as long as the server can serve the data with JSONP. What does JSONP look like? JSONP is a pretty simple 'protocol'. All it does is wrap a JSON response with a JavaScript function call. The above result from the JSONP call looks like this:Query17103401925975181569_1333408916499( [{"Id":"34043957","AlbumName":"Dirty Deeds Done Dirt Cheap",…},{…}] ) The way JSONP works is that the client (jQuery in this case) sends of the request, receives the response and evals it. The eval basically executes the function and deserializes the JSON inside of the function. It's actually a little more complex for the framework that does this, but that's the gist of what happens. JSONP works by executing the code that gets returned from the JSONP call. JSONP and ASP.NET Web API As mentioned previously, JSONP support is not natively in the box with ASP.NET Web API. But it's pretty easy to create and plug-in a custom formatter that provides this functionality. The following code is based on Christian Weyers example but has been updated to the latest Web API CodePlex bits, which changes the implementation a bit due to the way dependent objects are exposed differently in the latest builds. Here's the code:  using System; using System.IO; using System.Net; using System.Net.Http.Formatting; using System.Net.Http.Headers; using System.Threading.Tasks; using System.Web; using System.Net.Http; namespace Westwind.Web.WebApi { /// <summary> /// Handles JsonP requests when requests are fired with /// text/javascript or application/json and contain /// a callback= (configurable) query string parameter /// /// Based on Christian Weyers implementation /// https://github.com/thinktecture/Thinktecture.Web.Http/blob/master/Thinktecture.Web.Http/Formatters/JsonpFormatter.cs /// </summary> public class JsonpFormatter : JsonMediaTypeFormatter { public JsonpFormatter() { SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json")); SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/javascript")); //MediaTypeMappings.Add(new UriPathExtensionMapping("jsonp", "application/json")); JsonpParameterName = "callback"; } /// <summary> /// Name of the query string parameter to look for /// the jsonp function name /// </summary> public string JsonpParameterName {get; set; } /// <summary> /// Captured name of the Jsonp function that the JSON call /// is wrapped in. Set in GetPerRequestFormatter Instance /// </summary> private string JsonpCallbackFunction; public override bool CanWriteType(Type type) { return true; } /// <summary> /// Override this method to capture the Request object /// and look for the query string parameter and /// create a new instance of this formatter. /// /// This is the only place in a formatter where the /// Request object is available. /// </summary> /// <param name="type"></param> /// <param name="request"></param> /// <param name="mediaType"></param> /// <returns></returns> public override MediaTypeFormatter GetPerRequestFormatterInstance(Type type, HttpRequestMessage request, MediaTypeHeaderValue mediaType) { var formatter = new JsonpFormatter() { JsonpCallbackFunction = GetJsonCallbackFunction(request) }; return formatter; } /// <summary> /// Override to wrap existing JSON result with the /// JSONP function call /// </summary> /// <param name="type"></param> /// <param name="value"></param> /// <param name="stream"></param> /// <param name="contentHeaders"></param> /// <param name="transportContext"></param> /// <returns></returns> public override Task WriteToStreamAsync(Type type, object value, Stream stream, HttpContentHeaders contentHeaders, TransportContext transportContext) { if (!string.IsNullOrEmpty(JsonpCallbackFunction)) { return Task.Factory.StartNew(() => { var writer = new StreamWriter(stream); writer.Write( JsonpCallbackFunction + "("); writer.Flush(); base.WriteToStreamAsync(type, value, stream, contentHeaders, transportContext).Wait(); writer.Write(")"); writer.Flush(); }); } else { return base.WriteToStreamAsync(type, value, stream, contentHeaders, transportContext); } } /// <summary> /// Retrieves the Jsonp Callback function /// from the query string /// </summary> /// <returns></returns> private string GetJsonCallbackFunction(HttpRequestMessage request) { if (request.Method != HttpMethod.Get) return null; var query = HttpUtility.ParseQueryString(request.RequestUri.Query); var queryVal = query[this.JsonpParameterName]; if (string.IsNullOrEmpty(queryVal)) return null; return queryVal; } } } Note again that this code will not work with the Beta bits of Web API - it works only with post beta bits from CodePlex and hopefully this will continue to work until RTM :-) This code is a bit different from Christians original code as the API has changed. The biggest change is that the Read/Write functions no longer receive a global context object that gives access to the Request and Response objects as the older bits did. Instead you now have to override the GetPerRequestFormatterInstance() method, which receives the Request as a parameter. You can capture the Request there, or use the request to pick up the values you need and store them on the formatter. Note that I also have to create a new instance of the formatter since I'm storing request specific state on the instance (information whether the callback= querystring is present) so I return a new instance of this formatter. Other than that the code should be straight forward: The code basically writes out the function pre- and post-amble and the defers to the base stream to retrieve the JSON to wrap the function call into. The code uses the Async APIs to write this data out (this will take some getting used to seeing all over the place for me). Hooking up the JsonpFormatter Once you've created a formatter, it has to be added to the request processing sequence by adding it to the formatter collection. Web API is configured via the static GlobalConfiguration object.  protected void Application_Start(object sender, EventArgs e) { // Verb Routing RouteTable.Routes.MapHttpRoute( name: "AlbumsVerbs", routeTemplate: "albums/{title}", defaults: new { title = RouteParameter.Optional, controller = "AlbumApi" } ); GlobalConfiguration .Configuration .Formatters .Insert(0, new Westwind.Web.WebApi.JsonpFormatter()); }   That's all it takes. Note that I added the formatter at the top of the list of formatters, rather than adding it to the end which is required. The JSONP formatter needs to fire before any other JSON formatter since it relies on the JSON formatter to encode the actual JSON data. If you reverse the order the JSONP output never shows up. So, in general when adding new formatters also try to be aware of the order of the formatters as they are added. Resources JsonpFormatter Code on GitHub© Rick Strahl, West Wind Technologies, 2005-2012Posted in Web Api   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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• Hard drive device names are different from one reboot to another in Ubuntu.

  - by Mike

  I have an Ubuntu machine (10.04 but had the same problem in 8.04) with a bunch of drives that I use as a file server. 1 SATA that I boot off of. 2 IDE that in RAID1 and 2 SATA in RAID1. The problem is the drives that I have in RAID1 change device names on reboot. This is a problem because the in my mdadm.conf a reference to /dev/sda1, for example, might not work the next time I reboot because /dev/sda1 could be a disk from another array. Any help getting around this would be appreciated. -Mike

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• Hard drive device names are different from one reboot to another in Ubuntu.

  - by Mike

  I have an Ubuntu machine (10.04 but had the same problem in 8.04) with a bunch of drives that I use as a file server. 1 SATA that I boot off of. 2 IDE that in RAID1 and 2 SATA in RAID1. The problem is the drives that I have in RAID1 change device names on reboot. This is a problem because the in my mdadm.conf a reference to /dev/sda1, for example, might not work the next time I reboot because /dev/sda1 could be a disk from another array. Any help getting around this would be appreciated. -Mike

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• macport selfupdate not working

  - by eistrati

  macbookpro:~ eistrati$ port -v MacPorts 2.1.2 macbookpro:~ eistrati$ xcodebuild -version Xcode 4.5.2 Build version 4G2008a macbookpro:~ eistrati$ sudo port -d selfupdate DEBUG: Copying /Users/eistrati/Library/Preferences/com.apple.dt.Xcode.plist to /opt/local/var/macports/home/Library/Preferences DEBUG: MacPorts sources location: /opt/local/var/macports/sources/rsync.macports.org/release/tarballs ---> Updating MacPorts base sources using rsync rsync: failed to connect to rsync.macports.org: Connection refused (61) rsync error: error in socket IO (code 10) at /SourceCache/rsync/rsync-42/rsync/clientserver.c(105) [receiver=2.6.9] Command failed: /usr/bin/rsync -rtzv --delete-after rsync://rsync.macports.org/release/tarballs/base.tar /opt/local/var/macports/sources/rsync.macports.org/release/tarballs Exit code: 10 DEBUG: Error synchronizing MacPorts sources: command execution failed while executing "macports::selfupdate [array get global_options] base_updated" Error: /opt/local/bin/port: port selfupdate failed: Error synchronizing MacPorts sources: command execution failed Ideas? Please help!

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• My Favorite New Features in Visual Studio 2010

  On Tuesday, April 13th, Microsoft released Visual Studio 2010 and the .NET Framework 4.0 (which includes ASP.NET 4.0). To get started with Visual Studio 2010 you can either download a trial version of one of the commercial editions or you can go grab the free Visual Web Developer 2010 Express Edition. The Visual Studio 2010 user experience is noticeably different than with previous versions. Some of the changes are cosmetic - gone is the decades-old red and orange color scheme, having been replaced with blues and purples - while others are more substantial. For instance, the Visual Studio 2010 shell was rewritten from the ground up to use Microsoft's Windows Presentation Foundation (WPF). In addition to an updated user experience, Visual Studio introduces an array of new features designed to improve developer productivity. There are new tools for searching for files, types, and class members; it's now easier than ever to use IntelliSense; the Toolbox can be searched using the keyboard; and you can use a single editor - Visual Studio 2010 - to work on . This article explores some of the new features in Visual Studio 2010. It is not meant to be an exhaustive list, but rather highlights those features that I, as an ASP.NET developer, find most useful in my line of work. Read on to learn more! Read More >

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• My Favorite New Features in Visual Studio 2010

  On Tuesday, April 13th, Microsoft released Visual Studio 2010 and the .NET Framework 4.0 (which includes ASP.NET 4.0). To get started with Visual Studio 2010 you can either download a trial version of one of the commercial editions or you can go grab the free Visual Web Developer 2010 Express Edition. The Visual Studio 2010 user experience is noticeably different than with previous versions. Some of the changes are cosmetic - gone is the decades-old red and orange color scheme, having been replaced with blues and purples - while others are more substantial. For instance, the Visual Studio 2010 shell was rewritten from the ground up to use Microsoft's Windows Presentation Foundation (WPF). In addition to an updated user experience, Visual Studio introduces an array of new features designed to improve developer productivity. There are new tools for searching for files, types, and class members; it's now easier than ever to use IntelliSense; the Toolbox can be searched using the keyboard; and you can use a single editor - Visual Studio 2010 - to work on . This article explores some of the new features in Visual Studio 2010. It is not meant to be an exhaustive list, but rather highlights those features that I, as an ASP.NET developer, find most useful in my line of work. Read on to learn more! Read More >Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Windows 7 file sharing password protecting or making stuff available to just me

  - by Carbonara

  Even with the new Homegroup feature I'm still finding the way Windows deals with folder sharing utterly baffling. Here's what I want to do. I have two computers, a PC Desktop and a laptop. I also live in a shared flat with other computer users. I have set up a Homegroup and a Workgroup on the desktop and joined them on the laptop and in the home group I have shared video, music and pictures. This is so that anyone on the network can view pictures and listen to music etc. But I want my Documents folder from my desktop to only be available to me on my laptop and not to anyone else that may be on the network. The Homegroup only allows (from what I can gather from the baffling array of options) sharing with everyone or no one. Is it possible to only allow the laptop to access the documents folder on the desktop? The user name and password are the same on both computers.

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• My Optimized Adam &amp; Eve

  - by MarkPearl

  Today I had a few minutes in the evening to go over my original Adam and Eve code… what I wanted to see tonight was if I could optimize the code any further… which I was pretty sure could be done. Ultimately what I wanted to find from the experiment was a balance between optimized code an reusable code. On the one hand I can put everything into a single function and end up with a totally unusable function that is extremely compressed, which would have big comebacks when making modifications at a later stage. Alternatively I could have many single line functions that are extremely loosely coupled but sparsely spaced and so would almost be to fragmented to grok. Ultimately I found with my current iteration something that I consider readable, yet compressed. Code below… // Learn more about F# at http://fsharp.net open System let people = [ ("Adam", None); ("Eve", None); ("Cain", Some("Adam", "Eve")); ("Abel", Some("Adam", "Eve")) ] // // Prints the details // let showDetails(person : string * (string * string) option) = let ParentsName = let parents = snd(person) match parents with | Some(dad, mum) -> "Father " + dad + " and Mother " + mum | None -> "Has no parents!" let result = fst(person) + Environment.NewLine + ParentsName result // // Searches an array of people and looks for a match of names // let findPerson(name : string, people : (string * (string * string) option) list) = // Try and find a match of the name let o = Seq.tryFind(fun person -> match name with | firstName when firstName = fst(person) -> true | _ -> false) people // Show the details based on the match result match o with | Option.Some(x) -> showDetails(Option.get(o)) | _ -> "Not Found" Console.WriteLine(findPerson("Cains", people)) Console.ReadLine()

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• ASP.NET MVC localization DisplayNameAttribute alternatives: a good way

  - by Brian Schroer

  The ASP.NET MVC HTML helper methods like .LabelFor and .EditorFor use model metadata to autogenerate labels for model properties. By default it uses the property name for the label text, but if that’s not appropriate, you can use a DisplayName attribute to specify the desired label text: [DisplayName("Remember me?")] public bool RememberMe { get; set; } I’m working on a multi-language web site, so the labels need to be localized. I tried pointing the DisplayName attribute to a resource string: [DisplayName(MyResource.RememberMe)] public bool RememberMe { get; set; } …but that results in the compiler error "An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type”. I got around this by creating a custom LocalizedDisplayNameAttribute class that inherits from DisplayNameAttribute: 1: public class LocalizedDisplayNameAttribute : DisplayNameAttribute 2: { 3: public LocalizedDisplayNameAttribute(string resourceKey) 4: { 5: ResourceKey = resourceKey; 6: } 7:   8: public override string DisplayName 9: { 10: get 11: { 12: string displayName = MyResource.ResourceManager.GetString(ResourceKey); 13:   14: return string.IsNullOrEmpty(displayName) 15: ? string.Format("[[{0}]]", ResourceKey) 16: : displayName; 17: } 18: } 19:   20: private string ResourceKey { get; set; } 21: } Instead of a display string, it takes a constructor argument of a resource key. The DisplayName method is overridden to get the display string from the resource file (line 12). If the key is not found, I return a formatted string containing the key (e.g. “[[RememberMe]]”) so I can tell by looking at my web pages which resource keys I haven’t defined yet (line 15). The usage of my custom attribute in the model looks like this: [LocalizedDisplayName("RememberMe")] public bool RememberMe { get; set; } That was my first attempt at localized display names, and it’s a technique that I still use in some cases, but in my next post I’ll talk about the method that I now prefer, a custom DataAnnotationsModelMetadataProvider class…

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• Power supply triggered to start by another power supply

  - by steampowered

  I am building a raid array in a separate enclosure. I will be putting an empty tower case next to an existing tower computer, and this second tower case will only hold hard drives. There are many solutions for connecting the drives in the second case to the raid card in the first case (SFF-8088 and SFF-8087 cables). But I prefer not to run power from the first case to the second case. Can I use a power supply in the first tower case and cause it to start the power supply in the second case based on an indication from power in the first tower case's power supply? Maybe run a 12 volt cable from the first case to the power supply on the second case only for the purpose of initiating the second power supply.

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• It’s On! Oracle Open World 2012 Opens Call for Papers is Open

  - by David Hope-Ross

  Oracle OpenWorld is among the world’s largest industry events for good reason. It offers a vast array of learning and networking opportunities in one of the planet’s great cities.  And one of the key reasons for its popularity among procurement and supply chain professionals is the prominence of presentations by customers.   If you’d like to deliver a presentation based on your experience, now is the time to submit your abstract for review by the selection panel. The competition is strong: roughly 18% of entries are accepted each year from more than 3,000 submissions. Review panels are made up of experts both internal and external to Oracle. Successful submissions often (but not exclusively) focus on customer successes, how-tos, or best practices. What’s in it for you? Recognition, for one thing. Accepted sessions are publicized in the content catalog, which goes live in mid-June, and sessions given by external speakers often prove the most popular. Plus, accepted speakers get a complimentary pass to Oracle OpenWorld with access to all sessions and networking events- that could save you up to $2,595!   Be sure designate your session for inclusion in the correct track by selecting  “APPLICATIONS: Supply Chain Management” or “APPLICATIONS: Sourcing and Procurement” from the Primary Track drop down menu.   We look forward to seeing you in San Francisco!

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• many partitions on a single filegroup?¿ does it make sense?

  - by river0

  Hi, I'm designing a datawarehouse solution and I'm a newbie in disk configuration issues, let me explain you. Our storage is spread over 6 storage enlosures having each of them 5 raid-1 disk arrays, and having 2 LUNS defined per each disk array, which makes a total 48 LUNS (this is following Microsoft fast track recommendations for datawarehouse architectures). I would like to partition my data, on other projects I have worked before, we always followed a 1 partition - 1 filegroup rule. On the microsoft fast track recomendations it is advised to create a filegroup and then for that filegroup a data file per each lun... but I pretend to have a week level partitioning... if I apply that rule I think that I'll get too many files and a complex layout. I'm thinking of just creating just one filegroup (with the 48 lun data files), but still create the partitions since I want to keep soem of the benefits of partitions like partition switching... Is this scenario not recommended? What would you suggest?

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• News about Oracle Documaker Enterprise Edition

  - by Susanne Hale

  Updates come from the Documaker front on two counts: Oracle Documaker Awarded XCelent Award for Best Functionality Celent has published a NEW report entitled Document Automation Solution Vendors for Insurers 2011. In the evaluation, Oracle received the XCelent award for Functionality, which recognizes solutions as the leader in this category of the evaluation. According to Celent, “Insurers need to address issues related to the creation and handling of all sorts of documents. Key issues in document creation are complexity and volume. Today, most document automation vendors provide an array of features to cope with the complexity and volume of documents insurers need to generate.” The report ranks ten solution providers on Technology, Functionality, Market Penetration, and Services. Each profile provides detailed information about the vendor and its document automation system, the professional services and support staff it offers, product features, insurance customers and reference feedback, its technology, implementation process, and pricing.  A summary of the report is available at Celent’s web site. Documaker User Group in Wisconsin Holds First Meeting Oracle Documaker users in Wisconsin made the first Documaker User Group meeting a great success, with representation from eight companies. On April 19, over 25 attendees got together to share information, best practices, experiences and concepts related to Documaker and enterprise document automation; they were also able to share feedback with Documaker product management. One insurer shared how they publish and deliver documents to both internal and external customers as quickly and cost effectively as possible, since providing point of sale documents to the sales force in real time is crucial to obtaining and maintaining the book of business. They outlined best practices that ensure consistent development and testing strategies processes are in place to maximize performance and reliability. And, they gave an overview of the supporting applications they developed to monitor and improve performance as well as monitor and track each transaction. Wisconsin User Group meeting photos are posted on the Oracle Insurance Facebook page http://www.facebook.com/OracleInsurance. The Wisconsin User Group will meet again on October 26. If you and other Documaker customers in your area are interested in setting up a user group in your area, please contact Susanne Hale ([email protected]), (703) 927-0863.

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• RAID5 over LVM on Ubuntu Server 12.04.3

  - by April Ethereal

  I'm trying to create a RAID5 software array using LVM. I use VirtualBox as I'm only learning how LVM works. So I've created 4 virtual SCSI drives and then did the following: pvcreate /dev/sd[b-e] vgcreate /dev/sd[b-e] raid5_vg lvcreate --type raid5 -i 3 -L 1G -n raid_lv raid5_vg However, I get an error after the last command: WARNING: Unrecognised segment type raid5 Using default stripesize 64.00 KiB Rounding size (256 extents) up to stripe boundary size (258 extents) Cannot update volume group raid5_vg with unknown segments in it! So it looks like raid5 is not a valid segment type. "lvm segtypes" also doesn't contain 'raid5' entry: root@ubuntu-lvm:~# lvm segtypes striped zero error free snapshot mirror So my question is - how could I create RAID5 logical volume using LVM only? It seems that it is possible, I saw a few references (not for Ubuntu, unfortunately) for RedHat and Gentoo systems. I don't want to use mdadm for now, until I find out that it is mandatory. Some info about my system is below: root@ubuntu-lvm:~# uname -a Linux ubuntu-lvm 3.8.0I use Ubuntu Server 12.04.3 (i686)-29-generic #42~precise1-Ubuntu SMP Wed Aug 14 15:31:16 UTC 2013 i686 i686 i386 GNU/Linux root@ubuntu-lvm:~# dpkg -l | grep lvm ii lvm2 2.02.66-4ubuntu7.3 The Linux Logical Volume Manager Thanks.

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• Single/Mulitple LUN for vmware vm hosting

  - by Yucong Sun

  I'm building a iscsi storage system for hosting about ~500 Vmware vm running concurrently. And I have a disk array with 15 disks, I only need moderate write performance but preferably not SPOFed. so, that leaves me with RAID1 / RAID10 , I have couple choices: 1) 3x LUN 4disk RAID10 + 3 hot-swap 2) 1x LUN 14disk RAID10 + 1 hot-swap 3) 7x LUN 2disk RAID1 + 1 host-swap Which way is better? Is there a real problem running 500 vms on single LUN? and would it be better to resort to 7 LUns so each VM is better isolated with each other?

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• Linux software raid robustness

  - by Waxhead

  I have a 4 disk 5TB raid5 setup where a disk is showing signs of going down the drain. It is reporting media errors and from dmesg I can see that several read errors are corrected. smartctl does report "notifications" but no panic so far. Since new disks are rather expensive at the moment I am starting to pondering exactly how robust the linux md layer is. I would appreciate if someone could shed some light on how md actually deals with disk errors. For example how does md deal with write and read errors - what does it (really) take for disk to be rejected from an array. I also read that recently md got support for mapping out bad blocks. Does this mean that the read errors I've had would have been mapped out if I where running kernel 3.1 or would md still try to "work on them" to make them usable.

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• RAID 0 performance gains?

  - by NickAldwin

  I'm building a new computer over the summer. I'm fairly competent in computer hardware, and am thus building the computer from scratch. I have everything planned out, but I was wondering about RAID. I asked which RAID I should use earlier, but now that it's pretty clear that RAID 1 isn't really that great, I think I'll go with cloud-backup instead of disk-redundancy. However, I still face a choice: use two 1TB drives as two 1TB drives, or combine them into a RAID 0 striped array. Is there any performance gain at all? I know that if one drive dies, everything is gone, so is the performance gain worth it? I'm building a pretty advanced computer, with SLI video cards and a fast CPU, so I'm thinking RAID 0 would give me some good hard drive performance. From your experience, is RAID 0 viable?

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• Using Take and skip keyword to filter records in LINQ

  - by vik20000in

  In LINQ we can use the take keyword to filter out the number of records that we want to retrieve from the query. Let’s say we want to retrieve only the first 5 records for the list or array then we can use the following query     int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 };     var first3Numbers = numbers.Take(3); The TAKE keyword can also be easily applied to list of object in the following way. var first3WAOrders = (         from cust in customers         from order in cust.Orders         select cust ) .Take(3); [Note in the query above we are using the order clause so that the data is first ordered based on the orders field and then the first 3 records are taken. In both the above example we have been able to filter out data based on the number of records we want to fetch. But in both the cases we were fetching the records from the very beginning. But there can be some requirements whereby we want to fetch the records after skipping some of the records like in paging. For this purpose LINQ has provided us with the skip method which skips the number of records passed as parameter in the result set. int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; var allButFirst4Numbers = numbers.Skip(4); The SKIP keyword can also be easily applied to list of object in the following way. var first3WAOrders = (         from cust in customers         from order in cust.Orders         select cust ).Skip(3);  Vikram

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• Remote RAID Control ESXi Dell PowerEdge 2950 OpenManage

  - by yoyomommy

  I was wondering how one can add a drive into an existing RAID array while ESXi is still running. I have read that you are able to use Dell OpenManage to do this. I have installed OMSA 7.0 on the VMWare ESXi host (5.0 and fully updated) and I've installed OpenManage Essentials on a Windows Server 2008 R2 guest. The issue that I'm having is that OpenManage is unable to see my RAID controller. I have seen videos and photos as parts of guides on how to do this online, so I would assume that the functionality exists and I just have it set up wrong.

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• How to make a file load in my program when a user double clicks an associated file.

  - by Edward Boyle

  I assume in this article that file extension association has been setup by the installer. I may address file extension association at a later date, but for the purpose of this article, I address what sometimes eludes new C# programmers. This is sometimes confusing because you just don’t think about it — you have to access a file that you rarely access when making Windows forms applications, “Program.cs” static class Program { /// /// The main entry point for the application. /// [STAThread] static void Main() { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Application.Run(new Form1()); } } There are so many ways to skin this cat, so you get to see how I skinned my last cat. static class Program { /// /// The main entry point for the application. /// [STAThread] static void Main(string[] args) { Application.EnableVisualStyles(); Application.SetCompatibleTextRenderingDefault(false); Form1 mainf = new Form1(); if (args.Length > 0) { try { if (System.IO.File.Exists(args[0])) { mainf.LoadFile= args[0]; } } catch { MessageBox.Show("Could not open file.", "Could not open file.", MessageBoxButtons.OK, MessageBoxIcon.Information); } } Application.Run(mainf); } } It may be easy to miss, but don’t forget to add the string array for the command line arguments: static void Main(string[] args) this is not a part of the default program.cs You will notice the mainf.LoadFile property. In the main form of my program I have a property for public string LoadFile ... and the field private string loadFile = String.Empty; in the forms load event I check the value of this field. private void Form1_Load(object sender, EventArgs e) { if(loadFile != String.Empty){ // The only way this field is NOT String.empty is if we set it in // static void Main() of program.cs // LOAD it however it is needed OpenFile, SetDatabase, whatever you use. } }

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• How to Avoid Your Next 12-Month Science Project

  - by constant

  While most customers immediately understand how the magic of Oracle's Hybrid Columnar Compression, intelligent storage servers and flash memory make Exadata uniquely powerful against home-grown database systems, some people think that Exalogic is nothing more than a bunch of x86 servers, a storage appliance and an InfiniBand (IB) network, built into a single rack. After all, isn't this exactly what the High Performance Computing (HPC) world has been doing for decades? On the surface, this may be true. And some people tried exactly that: They tried to put together their own version of Exalogic, but then they discover there's a lot more to building a system than buying hardware and assembling it together. IT is not Ikea. Why is that so? Could it be there's more going on behind the scenes than merely putting together a bunch of servers, a storage array and an InfiniBand network into a rack? Let's explore some of the special sauce that makes Exalogic unique and un-copyable, so you can save yourself from your next 6- to 12-month science project that distracts you from doing real work that adds value to your company. Engineering Systems is Hard Work! The backbone of Exalogic is its InfiniBand network: 4 times better bandwidth than even 10 Gigabit Ethernet, and only about a tenth of its latency. What a potential for increased scalability and throughput across the middleware and database layers! But InfiniBand is a beast that needs to be tamed: It is true that Exalogic uses a standard, open-source Open Fabrics Enterprise Distribution (OFED) InfiniBand driver stack. Unfortunately, this software has been developed by the HPC community with fastest speed in mind (which is good) but, despite the name, not many other enterprise-class requirements are included (which is less good). Here are some of the improvements that Oracle's InfiniBand development team had to add to the OFED stack to make it enterprise-ready, simply because typical HPC users didn't have the need to implement them: More than 100 bug fixes in the pieces that were not related to the Message Passing Interface Protocol (MPI), which is the protocol that HPC users use most of the time, but which is less useful in the enterprise. Performance optimizations and tuning across the whole IB stack: From Switches, Host Channel Adapters (HCAs) and drivers to low-level protocols, middleware and applications. Yes, even the standard HPC IB stack could be improved in terms of performance. Ethernet over IB (EoIB): Exalogic uses InfiniBand internally to reach high performance, but it needs to play nicely with datacenters around it. That's why Oracle added Ethernet over InfiniBand technology to it that allows for creating many virtual 10GBE adapters inside Exalogic's nodes that are aggregated and connected to Exalogic's IB gateway switches. While this is an open standard, it's up to the vendor to implement it. In this case, Oracle integrated the EoIB stack with Oracle's own IB to 10GBE gateway switches, and made it fully virtualized from the beginning. This means that Exalogic customers can completely rewire their server infrastructure inside the rack without having to physically pull or plug a single cable - a must-have for every cloud deployment. Anybody who wants to match this level of integration would need to add an InfiniBand switch development team to their project. Or just buy Oracle's gateway switches, which are conveniently shipped with a whole server infrastructure attached! IPv6 support for InfiniBand's Sockets Direct Protocol (SDP), Reliable Datagram Sockets (RDS), TCP/IP over IB (IPoIB) and EoIB protocols. Because no IPv6 = not very enterprise-class. HA capability for SDP. High Availability is not a big requirement for HPC, but for enterprise-class application servers it is. Every node in Exalogic's InfiniBand network is connected twice for redundancy. If any cable or port or HCA fails, there's always a replacement link ready to take over. This requires extra magic at the protocol level to work. So in addition to Weblogic's failover capabilities, Oracle implemented IB automatic path migration at the SDP level to avoid unnecessary failover operations at the middleware level. Security, for example spoof-protection. Another feature that is less important for traditional users of InfiniBand, but very important for enterprise customers. InfiniBand Partitioning and Quality-of-Service (QoS): One of the first questions we get from customers about Exalogic is: “How can we implement multi-tenancy?” The answer is to partition your IB network, which effectively creates many networks that work independently and that are protected at the lowest networking layer possible. In addition to that, QoS allows administrators to prioritize traffic flow in multi-tenancy environments so they can keep their service levels where it matters most. Resilient IB Fabric Management: InfiniBand is a self-managing network, so a lot of the magic lies in coming up with the right topology and in teaching the subnet manager how to properly discover and manage the network. Oracle's Infiniband switches come with pre-integrated, highly available fabric management with seamless integration into Oracle Enterprise Manager Ops Center. In short: Oracle elevated the OFED InfiniBand stack into an enterprise-class networking infrastructure. Many years and multiple teams of manpower went into the above improvements - this is something you can only get from Oracle, because no other InfiniBand vendor can give you these features across the whole stack! Exabus: Because it's not About the Size of Your Network, it's How You Use it! So let's assume that you somehow were able to get your hands on an enterprise-class IB driver stack. Or maybe you don't care and are just happy with the standard OFED one? Anyway, the next step is to actually leverage that InfiniBand performance. Here are the choices: Use traditional TCP/IP on top of the InfiniBand stack, Develop your own integration between your middleware and the lower-level (but faster) InfiniBand protocols. While more bandwidth is always a good thing, it's actually the low latency that enables superior performance for your applications when running on any networking infrastructure: The lower the latency, the faster the response travels through the network and the more transactions you can close per second. The reason why InfiniBand is such a low latency technology is that it gets rid of most if not all of your traditional networking protocol stack: Data is literally beamed from one region of RAM in one server into another region of RAM in another server with no kernel/drivers/UDP/TCP or other networking stack overhead involved! Which makes option 1 a no-go: Adding TCP/IP on top of InfiniBand is like adding training wheels to your racing bike. It may be ok in the beginning and for development, but it's not quite the performance IB was meant to deliver. Which only leaves option 2: Integrating your middleware with fast, low-level InfiniBand protocols. And this is what Exalogic's "Exabus" technology is all about. Here are a few Exabus features that help applications leverage the performance of InfiniBand in Exalogic: RDMA and SDP integration at the JDBC driver level (SDP), for Oracle Weblogic (SDP), Oracle Coherence (RDMA), Oracle Tuxedo (RDMA) and the new Oracle Traffic Director (RDMA) on Exalogic. Using these protocols, middleware can communicate a lot faster with each other and the Oracle database than by using standard networking protocols, Seamless Integration of Ethernet over InfiniBand from Exalogic's Gateway switches into the OS, Oracle Weblogic optimizations for handling massive amounts of parallel transactions. Because if you have an 8-lane Autobahn, you also need to improve your ramps so you can feed it with many cars in parallel. Integration of Weblogic with Oracle Exadata for faster performance, optimized session management and failover. As you see, “Exabus” is Oracle's word for describing all the InfiniBand enhancements Oracle put into Exalogic: OFED stack enhancements, protocols for faster IB access, and InfiniBand support and optimizations at the virtualization and middleware level. All working together to deliver the full potential of InfiniBand performance. Who else has 100% control over their middleware so they can develop their own low-level protocol integration with InfiniBand? Even if you take an open source approach, you're looking at years of development work to create, test and support a whole new networking technology in your middleware! The Extras: Less Hassle, More Productivity, Faster Time to Market And then there are the other advantages of Engineered Systems that are true for Exalogic the same as they are for every other Engineered System: One simple purchasing process: No headaches due to endless RFPs and no “Will X work with Y?” uncertainties. Everything has been engineered together: All kinds of bugs and problems have been already fixed at the design level that would have only manifested themselves after you have built the system from scratch. Everything is built, tested and integrated at the factory level . Less integration pain for you, faster time to market. Every Exalogic machine world-wide is identical to Oracle's own machines in the lab: Instant replication of any problems you may encounter, faster time to resolution. Simplified patching, management and operations. One throat to choke: Imagine finger-pointing hell for systems that have been put together using several different vendors. Oracle's Engineered Systems have a single phone number that customers can call to get their problems solved. For more business-centric values, read The Business Value of Engineered Systems. Conclusion: Buy Exalogic, or get ready for a 6-12 Month Science Project And here's the reason why it's not easy to "build your own Exalogic": There's a lot of work required to make such a system fly. In fact, anybody who is starting to "just put together a bunch of servers and an InfiniBand network" is really looking at a 6-12 month science project. And the outcome is likely to not be very enterprise-class. And it won't have Exalogic's performance either. Because building an Engineered System is literally rocket science: It takes a lot of time, effort, resources and many iterations of design/test/analyze/fix to build such a system. That's why InfiniBand has been reserved for HPC scientists for such a long time. And only Oracle can bring the power of InfiniBand in an enterprise-class, ready-to use, pre-integrated version to customers, without the develop/integrate/support pain. For more details, check the new Exalogic overview white paper which was updated only recently. P.S.: Thanks to my colleagues Ola, Paul, Don and Andy for helping me put together this article! var flattr_uid = '26528'; var flattr_tle = 'How to Avoid Your Next 12-Month Science Project'; var flattr_dsc = 'While most customers immediately understand how the magic of Oracle's Hybrid Columnar Compression, intelligent storage servers and flash memory make Exadata uniquely powerful against home-grown database systems, some people think that Exalogic is nothing more than a bunch of x86 servers, a storage appliance and an InfiniBand (IB) network, built into a single rack.After all, isn't this exactly what the High Performance Computing (HPC) world has been doing for decades?On the surface, this may be true. And some people tried exactly that: They tried to put together their own version of Exalogic, but then they discover there's a lot more to building a system than buying hardware and assembling it together. IT is not Ikea.Why is that so? Could it be there's more going on behind the scenes than merely putting together a bunch of servers, a storage array and an InfiniBand network into a rack? Let's explore some of the special sauce that makes Exalogic unique and un-copyable, so you can save yourself from your next 6- to 12-month science project that distracts you from doing real work that adds value to your company.'; var flattr_tag = 'Engineered Systems,Engineered Systems,Infiniband,Integration,latency,Oracle,performance'; var flattr_cat = 'text'; var flattr_url = 'http://constantin.glez.de/blog/2012/04/how-avoid-your-next-12-month-science-project'; var flattr_lng = 'en_GB'

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• grow/shrink a zfs RAIDZ

  - by c2h2

  I'm going to build a freenas server, would like to make sure what I can do with such magical and advanced zfs. If I have 5 * 3TB disks in RAIDZ (12TB storage in total), now I am trying to add another 2 * 3TB disks to this existing array. Q: Am I able to do it without affect/touch any existing data on RAIDZ volume? What about take away some existing disk? say take away 1 disk out of the 5 disks, assuming only very small portion of data exists on the raidz.

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• cpanel api fileman alternative

  - by Coombesy

  trying to remotely unpack a zip file, then move the contents on cpanel servers. Some research led me to xmlApi class and the fileman module. And here my problem lies as Fileman module is returning html based on the cpanel theme (which we won't know) - and all I need is a list of files. here is the code flow: * using ftp, the zip is uploaded * using Fileman module unpack zip * loop through unpacked files and move here is my call to list the files: $files_html = $xml->api1_query($user, "Fileman", "listfiles", array( "{$ftp_dir}", //source dir 0 //chooser )); and it is returning the html for the filemanager - which is going to be different based on the cpanel theme. Surely their has to be another way to simply just list the files in that directory? any help would be appreciated, been researching this for past day and can't find solution anywhere. cheers ;)

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• The fastest way to resize images from ASP.NET. And it’s (more) supported-ish.

  - by Bertrand Le Roy

  I’ve shown before how to resize images using GDI, which is fairly common but is explicitly unsupported because we know of very real problems that this can cause. Still, many sites still use that method because those problems are fairly rare, and because most people assume it’s the only way to get the job done. Plus, it works in medium trust. More recently, I’ve shown how you can use WPF APIs to do the same thing and get JPEG thumbnails, only 2.5 times faster than GDI (even now that GDI really ultimately uses WIC to read and write images). The boost in performance is great, but it comes at a cost, that you may or may not care about: it won’t work in medium trust. It’s also just as unsupported as the GDI option. What I want to show today is how to use the Windows Imaging Components from ASP.NET APIs directly, without going through WPF. The approach has the great advantage that it’s been tested and proven to scale very well. The WIC team tells me you should be able to call support and get answers if you hit problems. Caveats exist though. First, this is using interop, so until a signed wrapper sits in the GAC, it will require full trust. Second, the APIs have a very strong smell of native code and are definitely not .NET-friendly. And finally, the most serious problem is that older versions of Windows don’t offer MTA support for image decoding. MTA support is only available on Windows 7, Vista and Windows Server 2008. But on 2003 and XP, you’ll only get STA support. that means that the thread safety that we so badly need for server applications is not guaranteed on those operating systems. To make it work, you’d have to spin specialized threads yourself and manage the lifetime of your objects, which is outside the scope of this article. We’ll assume that we’re fine with al this and that we’re running on 7 or 2008 under full trust. Be warned that the code that follows is not simple or very readable. This is definitely not the easiest way to resize an image in .NET. Wrapping native APIs such as WIC in a managed wrapper is never easy, but fortunately we won’t have to: the WIC team already did it for us and released the results under MS-PL. The InteropServices folder, which contains the wrappers we need, is in the WicCop project but I’ve also included it in the sample that you can download from the link at the end of the article. In order to produce a thumbnail, we first have to obtain a decoding frame object that WIC can use. Like with WPF, that object will contain the command to decode a frame from the source image but won’t do the actual decoding until necessary. Getting the frame is done by reading the image bytes through a special WIC stream that you can obtain from a factory object that we’re going to reuse for lots of other tasks: var photo = File.ReadAllBytes(photoPath); var factory = (IWICComponentFactory)new WICImagingFactory(); var inputStream = factory.CreateStream(); inputStream.InitializeFromMemory(photo, (uint)photo.Length); var decoder = factory.CreateDecoderFromStream( inputStream, null, WICDecodeOptions.WICDecodeMetadataCacheOnLoad); var frame = decoder.GetFrame(0); We can read the dimensions of the frame using the following (somewhat ugly) code: uint width, height; frame.GetSize(out width, out height); This enables us to compute the dimensions of the thumbnail, as I’ve shown in previous articles. We now need to prepare the output stream for the thumbnail. WIC requires a special kind of stream, IStream (not implemented by System.IO.Stream) and doesn’t directlyunderstand .NET streams. It does provide a number of implementations but not exactly what we need here. We need to output to memory because we’ll want to persist the same bytes to the response stream and to a local file for caching. The memory-bound version of IStream requires a fixed-length buffer but we won’t know the length of the buffer before we resize. To solve that problem, I’ve built a derived class from MemoryStream that also implements IStream. The implementation is not very complicated, it just delegates the IStream methods to the base class, but it involves some native pointer manipulation. Once we have a stream, we need to build the encoder for the output format, which could be anything that WIC supports. For web thumbnails, our only reasonable options are PNG and JPEG. I explored PNG because it’s a lossless format, and because WIC does support PNG compression. That compression is not very efficient though and JPEG offers good quality with much smaller file sizes. On the web, it matters. I found the best PNG compression option (adaptive) to give files that are about twice as big as 100%-quality JPEG (an absurd setting), 4.5 times bigger than 95%-quality JPEG and 7 times larger than 85%-quality JPEG, which is more than acceptable quality. As a consequence, we’ll use JPEG. The JPEG encoder can be prepared as follows: var encoder = factory.CreateEncoder( Consts.GUID_ContainerFormatJpeg, null); encoder.Initialize(outputStream, WICBitmapEncoderCacheOption.WICBitmapEncoderNoCache); The next operation is to create the output frame: IWICBitmapFrameEncode outputFrame; var arg = new IPropertyBag2[1]; encoder.CreateNewFrame(out outputFrame, arg); Notice that we are passing in a property bag. This is where we’re going to specify our only parameter for encoding, the JPEG quality setting: var propBag = arg[0]; var propertyBagOption = new PROPBAG2[1]; propertyBagOption[0].pstrName = "ImageQuality"; propBag.Write(1, propertyBagOption, new object[] { 0.85F }); outputFrame.Initialize(propBag); We can then set the resolution for the thumbnail to be 96, something we weren’t able to do with WPF and had to hack around: outputFrame.SetResolution(96, 96); Next, we set the size of the output frame and create a scaler from the input frame and the computed dimensions of the target thumbnail: outputFrame.SetSize(thumbWidth, thumbHeight); var scaler = factory.CreateBitmapScaler(); scaler.Initialize(frame, thumbWidth, thumbHeight, WICBitmapInterpolationMode.WICBitmapInterpolationModeFant); The scaler is using the Fant method, which I think is the best looking one even if it seems a little softer than cubic (zoomed here to better show the defects): Cubic Fant Linear Nearest neighbor We can write the source image to the output frame through the scaler: outputFrame.WriteSource(scaler, new WICRect { X = 0, Y = 0, Width = (int)thumbWidth, Height = (int)thumbHeight }); And finally we commit the pipeline that we built and get the byte array for the thumbnail out of our memory stream: outputFrame.Commit(); encoder.Commit(); var outputArray = outputStream.ToArray(); outputStream.Close(); That byte array can then be sent to the output stream and to the cache file. Once we’ve gone through this exercise, it’s only natural to wonder whether it was worth the trouble. I ran this method, as well as GDI and WPF resizing over thirty twelve megapixel images for JPEG qualities between 70% and 100% and measured the file size and time to resize. Here are the results: Size of resized images   Time to resize thirty 12 megapixel images Not much to see on the size graph: sizes from WPF and WIC are equivalent, which is hardly surprising as WPF calls into WIC. There is just an anomaly for 75% for WPF that I noted in my previous article and that disappears when using WIC directly. But overall, using WPF or WIC over GDI represents a slight win in file size. The time to resize is more interesting. WPF and WIC get similar times although WIC seems to always be a little faster. Not surprising considering WPF is using WIC. The margin of error on this results is probably fairly close to the time difference. As we already knew, the time to resize does not depend on the quality level, only the size does. This means that the only decision you have to make here is size versus visual quality. This third approach to server-side image resizing on ASP.NET seems to converge on the fastest possible one. We have marginally better performance than WPF, but with some additional peace of mind that this approach is sanctioned for server-side usage by the Windows Imaging team. It still doesn’t work in medium trust. That is a problem and shows the way for future server-friendly managed wrappers around WIC. The sample code for this article can be downloaded from: http://weblogs.asp.net/blogs/bleroy/Samples/WicResize.zip The benchmark code can be found here (you’ll need to add your own images to the Images directory and then add those to the project, with content and copy if newer in the properties of the files in the solution explorer): http://weblogs.asp.net/blogs/bleroy/Samples/WicWpfGdiImageResizeBenchmark.zip WIC tools can be downloaded from: http://code.msdn.microsoft.com/wictools To conclude, here are some of the resized thumbnails at 85% fant:

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