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  • Java Can't Find File when Running through Eclipse

    - by derekerdmann
    When I run a Java application that should be reading from a file in Eclipse, I get a java.io.FileNotFoundException, even though the file is in the correct directory. I can compile and run the application from the command line just fine; the problem only occurs in Eclipse, with more than one project and application. Is there a setting I need to change in the run configurations or build paths to get it to find the file correctly?

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  • Create all directories up to a point?

    - by Stefan Kendall
    I need to be able to build all directories up to and including the directory specified by my File object. For example, suppose I have something like this: File file = new File( "/var/a/b/c/d/" ); But only /var/ exists. I need a method that builds up to d, and I was wondering if there was a method in a java io library somewhere that does this already.

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  • C#, how to delete all files and folders in a directory?

    - by JL
    Using C#, how can I delete all files and folders from a directory, but still keep the root directory? I have this System.IO.DirectoryInfo downloadedMessageInfo = new DirectoryInfo(GetMessageDownloadFolderPath()); foreach (FileInfo file in downloadedMessageInfo.GetFiles()) { file.Delete(); } foreach (DirectoryInfo dir in downloadedMessageInfo.GetDirectories()) { dir.Delete(true); } Is this the cleanest way to do it?

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  • Is there a common way to access files, that works both on android and PC?

    - by m01
    Hi, I'm writing an application that will ship in two versions: Android and PC version. Is there a simple way to access files from the shared code? Using java.io is simple, but I don't know how to access android resources or assets using it. And I can't write methods that operate on FileInputStreams instead, because some files contain references to another ones, so I need a way to access them from the method code. Any suggestions?

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  • Java: Check if file is already open

    - by hello_world_infinity
    I need to write a custom batch File renamer. I've got the bulk of it done except I can't figure out how to check if a file is already open. I'm just using the java.io.File package and there is a canWrite() method but that doesn't seem to test if the file is in use by another program. Any ideas on how I can make this work?

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  • How to read a file from bottom to top in Ruby?

    - by two2twelve
    I've been working on a log viewer for a Rails app and have found that I need to read around 200 lines of a log file from bottom to top instead of the default top to bottom. Log files can get quite large, so I've already tried and ruled out the IO.readlines("log_file.log")[-200..-1] method. Are there any other ways to go about reading a file backwards in Ruby without the need for a plugin or gem?

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  • How do I mount a USB floppy disk drive?

    - by Jocky B
    I have tried to mount my usb floppy disk drive in 11.04 Natty. So far I have managed to use the udisks --mount/dev/sdf command in terminal, but get a message that I have not stated a filetype john@john-desktop:~$ udisks --mount /dev/sdf Mount failed: Error mounting: mount: you must specify the filesystem type This is the result I get when trying to mount the usb floppy disk drive. Anyone know how to proceed?

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  • Why is my dual-boot Ubuntu partition showing up as a peripheral "root.disk"?

    - by Don
    I recently installed Ubuntu 12.04, which I had been booting from a usb key, as a dual-boot on my machine running Windows 7. From what I had read online while researching, I was prepared to have to shrink the Windows partition and all that. But I never had to - it really was just a few clicks here and there and it was installed. I'm still pretty confused about it, but whatever, it worked, and the two peacefully coexist on my machine, and I have broken things to fix before I worry about fixing unbroken things. So yesterday I got it in my head to look at my partitions (I was considering making an all new partition to install the Windows 8 Release Preview). What I saw confused me. Here's a screenshot of the disk utility. At this moment, there is nothing connected to my computer, and nothing in any of the optical drives/ports/card readers/etc. Can you help me figure out what's going on here? Don's Machine is, I believe, my Windows partition - that's the name I assigned my machine from Windows Explorer. PQSERVICE is from what I can find online also Windows, but having to do with backup. And SYSTEM REQUIRED, if I browse it in Ubuntu, is definitely something to do with booting, and I believe it is also Windows'. According to the sizes shown, those three together should use up my 500 GB HD. Then further down, as a "peripheral device", it lists that 31 GB disk. This is obviously my Ubuntu (Model:Linux Loop:root.disk), but why is it showing up as a peripheral? So, to sum up those questions and to add some more random ones I had: Why is Ubuntu showing up as a peripheral device? If the Windows sections take up all 500 GB, where does Ubuntu live? If I renamed the disk partitions, would my life become a nightmare (seriously - can I safely rename them)? Why didn't I have to resize the Windows partition in the first place? Would giving Ubuntu more space improve its performance (it hangs alot)? Is it possible to have a partition for each OS (Windows 7 & 8, Ubuntu), a partition for files, and a separate partition for backups? Is this towards the good or bad idea end of the spectrum? @Elfy, would that explain why it keeps hanging? I guess I'll backup my files, rip it out, and reinstall it correctly later on today.

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  • How can i turn a virtualbox disk partion to be my main boot system? (read description)

    - by user75975
    I recently had windows xp installed on my pc and chose to try ubuntu but i did a full install with ubuntu. I luckily chose to create a backup windows iso before the install and now want to reinstall windows but i couldnt find a sufficient program to mount the iso to my cd disk. My question is how can i burn the disk using VirtualBox or even how can i transform a virtual box partion to my main OS system?? thx in advance

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  • Snow Leopard doesn't repair permissions, despite showing / saying its fixed them?

    - by Jules
    Sometime ago, I used carbon copy as I was replacing my hard drive in my Mac Mini running Snow Leopard. Afterwards, on my new drive I had some permission problems. I've tried several times running a repair permissions / repair disk from disk util. It shows that there are problems and I think it says its correceted the problems. However the problems remain, what can I do to fix them ? It doesn't seem to cause me any problems, that I can tell EDIT Repairing permissions for “Macintosh HD” Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Italian.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Italian.lproj/UIAgent.nib". Permissions differ on "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/jconsole.jar", should be -rw-r--r-- , they are lrwxr-xr-x . Repaired "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Classes/jconsole.jar". User differs on "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home/lib", should be 95, user is 0. Repaired "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home/lib". User differs on "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Libraries", should be 95, user is 0. Repaired "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Libraries". Permissions differ on "System/Library/Frameworks/JavaVM.framework/Versions/A/Resources/Deploy.bundle/Contents/Home/lib/security/cacerts", should be -rw-r--r-- , they are lrwxr-xr-x . Repaired "System/Library/Frameworks/JavaVM.framework/Versions/A/Resources/Deploy.bundle/Contents/Home/lib/security/cacerts". Permissions differ on "System/Library/Frameworks/JavaVM.framework/Versions/A/Resources/Deploy.bundle/Contents/Resources/Java/deploy.jar", should be -rw-r--r-- , they are lrwxr-xr-x . Repaired "System/Library/Frameworks/JavaVM.framework/Versions/A/Resources/Deploy.bundle/Contents/Resources/Java/deploy.jar". Permissions differ on "System/Library/Frameworks/JavaVM.framework/Versions/A/Resources/Deploy.bundle/Contents/Resources/Java/libdeploy.jnilib", should be -rwxr-xr-x , they are lrwxr-xr-x . Repaired "System/Library/Frameworks/JavaVM.framework/Versions/A/Resources/Deploy.bundle/Contents/Resources/Java/libdeploy.jnilib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreenLeopard386.app/Contents/Resources/Italian.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreenLeopard386.app/Contents/Resources/Italian.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/zh_TW.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/zh_TW.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/zh_TW.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/zh_TW.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/zh_TW.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/zh_TW.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/zh_CN.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/zh_CN.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/zh_CN.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/zh_CN.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/zh_CN.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/zh_CN.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/ko.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/ko.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/ko.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/ko.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/ko.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/ko.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Dutch.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Dutch.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Dutch.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Dutch.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Dutch.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Dutch.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Italian.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Italian.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Italian.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Italian.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Spanish.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Spanish.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Spanish.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Spanish.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Spanish.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Spanish.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/French.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/French.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/French.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/French.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/French.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/French.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/German.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/German.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/German.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/German.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/German.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/German.lproj/MainMenu.nib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Japanese.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/Japanese.lproj/RemoteDesktopMenu.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Japanese.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/Japanese.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Japanese.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Japanese.lproj/MainMenu.nib". Permissions differ on "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Resources/JavaPluginCocoa.bundle/Contents/Resources/Java/deploy.jar", should be -rw-r--r-- , they are lrwxr-xr-x . Repaired "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Resources/JavaPluginCocoa.bundle/Contents/Resources/Java/deploy.jar". Permissions differ on "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Resources/JavaPluginCocoa.bundle/Contents/Resources/Java/libdeploy.jnilib", should be -rwxr-xr-x , they are lrwxr-xr-x . Repaired "System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Resources/JavaPluginCocoa.bundle/Contents/Resources/Java/libdeploy.jnilib". Permissions differ on "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/English.lproj/RemoteDesktopMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/Menu Extras/RemoteDesktop.menu/Contents/Resources/English.lproj/RemoteDesktopMenu.nib". Warning: SUID file "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/MacOS/ARDAgent" has been modified and will not be repaired. Permissions differ on "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/English.lproj/UIAgent.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Support/Remote Desktop Message.app/Contents/Resources/English.lproj/UIAgent.nib". Permissions differ on "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/English.lproj/MainMenu.nib", should be drwxr-xr-x , they are -rwxr-xr-x . Repaired "System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/English.lproj/MainMenu.nib". Group differs on "private/var/log/kernel.log", should be 80, group is 0. Permissions differ on "private/var/log/kernel.log", should be -rw-r----- , they are -rw-r--r-- . Repaired "private/var/log/kernel.log". Group differs on "private/var/log/secure.log", should be 80, group is 0. Permissions differ on "private/var/log/secure.log", should be -rw-r----- , they are -rw-r--r-- . Repaired "private/var/log/secure.log". Group differs on "private/var/log/system.log", should be 80, group is 0. Permissions differ on "private/var/log/system.log", should be -rw-r----- , they are -rw-r--r-- . Repaired "private/var/log/system.log". Permissions repair complete

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  • Lots of questions about file I/O (reading/writing message strings)

    - by Nazgulled
    Hi, For this university project I'm doing (for which I've made a couple of posts in the past), which is some sort of social network, it's required the ability for the users to exchange messages. At first, I designed my data structures to hold ALL messages in a linked list, limiting the message size to 256 chars. However, I think my instructors will prefer if I save the messages on disk and read them only when I need them. Of course, they won't say what they prefer, I need to make a choice and justify the best I can why I went that route. One thing to keep in mind is that I only need to save the latest 20 messages from each user, no more. Right now I have an Hash Table that will act as inbox, this will be inside the user profile. This Hash Table will be indexed by name (the user that sent the message). The value for each element will be a data structure holding an array of size_t with 20 elements (20 messages like I said above). The idea is to keep track of the disk file offsets and bytes written. Then, when I need to read a message, I just need to use fseek() and read the necessary bytes. I think this could work nicely... I could use just one single file to hold all messages from all users in the network. I'm saying one single file because a colleague asked an instructor about saving the messages from each user independently which he replied that it might not be the best approach cause the file system has it's limits. That's why I'm thinking of going the single file route. However, this presents a problem... Since I only need to save the latest 20 messages, I need to discard the older ones when I reach this limit. I have no idea how to do this... All I know is about fread() and fwrite() to read/write bytes from/to files. How can I go to a file offset and say "hey, delete the following X bytes"? Even if I could do that, there's another problem... All offsets below that one will be completely different and I would have to process all users mailboxes to fix the problem. Which would be a pain... So, any suggestions to solve my problems? What do you suggest?

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  • To clone or to automate a system installation?

    - by Shtééf
    Let's say you're setting up a cluster of servers performing the same task. Or say you're just setting up a bunch of different servers, but you expect to use a base configuration on all of your servers. Would it be better practice to create a base image and clone it, or to automate the installation and configuration? I occasionally end up in this argument with my boss, in situations where we're time-pressed. When he sees me struggle with perfecting the automation, his suggestion is often to clone the entire disk to the other machines. But my instinct has always been to avoid cloning. This is mostly from an Ubuntu perspective, but the question is fairly general. My reasons for avoiding cloning are: On a typical install, even if it's fresh, there are already several unique identifiers installed: filesystem UUIDs, SSH host keys, among others. These would have to be regenerated. Network needs to be reconfigured for each clone. This would need to be done off-line, of course, or the settings will conflict with other machines on the network. On the other hand, some of the cloning advantages are quite clear as well: (Initially?) less effort required than automating configuration. Tools exist to quickly address (some) of the above disadvantages. (I can see right through my own bias there.)

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  • Variable size encrypted container

    - by Cray
    Is there an application similar to TrueCrypt, but the one that can make variable size containers opposed to fixed-size or only-growing-to-certain-amount containers which can be made by TrueCrypt? I want this container to be able to be mounted to a drive/folder, and the size of the outer container not be much different from the total size of all the files that I put into the mounted folder, while still providing strong encryption. If to put it in other words, I want a program like truecrypt, which not only automatically grows the container if I put in new files, but also decreases it's size if some files are deleted. I know there are some issues of course, and it would not work 100% as truecrypt, because it basically works on the sector level of the disk, giving all the filesystem-control to the OS, and so when I remove a file, it might as well be left there, or there might be some fragmentation issues that would stop just truncating the volume from working, but perhaps a program can be built in some other way? Instead of providing sector-level interface, it would provide filesystem-level interface? A filesystem inside a file which would support shrinking when files are deleted?

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  • Ubuntu raid 1 write errors

    - by Micah
    I have an Ubuntu server set up with two SATA drives in a RAID 1 configuration with MDADM. The machine is used to record raw video, which involves a lot of writing to the disk. Sometimes during video recording the computer will crash, will the following errors in kern.log: Mar 15 10:39:41 video kernel: [414501.629864] ata2.00: exception Emask 0x10 SAct 0x0 SErr 0x400100 action 0x6 Mar 15 10:39:41 video kernel: [414501.629870] ata2.00: BMDMA stat 0x26 Mar 15 10:39:41 video kernel: [414501.629875] ata2.00: SError: { UnrecovData Handshk } Mar 15 10:39:41 video kernel: [414501.629880] ata2.00: failed command: WRITE DMA EXT Mar 15 10:39:41 video kernel: [414501.629889] ata2.00: cmd 35/00:00:28:6d:f6/00:04:06:00:00/e0 tag 0 dma 524288 out Mar 15 10:39:41 video kernel: [414501.629891] res 51/84:b1:77:6e:f6/84:02:06:00:00/e0 Emask 0x30 (host bus error) Mar 15 10:39:41 video kernel: [414501.629896] ata2.00: status: { DRDY ERR } Mar 15 10:39:41 video kernel: [414501.629899] ata2.00: error: { ICRC ABRT } Mar 15 10:39:41 video kernel: [414501.629910] ata2.00: hard resetting link Mar 15 10:39:41 video kernel: [414501.973009] ata2.01: hard resetting link Mar 15 10:39:41 video kernel: [414502.482642] ata2.00: SATA link up 3.0 Gbps (SStatus 123 SControl 300) Mar 15 10:39:41 video kernel: [414502.482658] ata2.01: SATA link down (SStatus 0 SControl 300) Mar 15 10:39:41 video kernel: [414502.546160] ata2.00: configured for UDMA/133 Mar 15 10:39:41 video kernel: [414502.546203] ata2: EH complete Is this the result of faulty drives? Is software RAID just not performant enough for data rates ~15 MB/s, even with a quad-core i7? Thanks for your help. Edit: cat /proc/mdstat returns this: Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sdb1[1] sda1[0] 976760768 blocks [2/2] [UU] unused devices: <none>

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  • Very slow write performance on Debian 6.0 (AMD64) with DMCRYPT/LVM/RAID1

    - by jdelic
    I'm seeing very strange performance characteristics on one of my servers. This server is running a simple two-disk software-RAID1 setup with LVM spanning /dev/md0. One of the logical volumes /dev/vg0/secure is encrypted using dmcrypt with LUKS and mounted with the sync and noatimes flag. Writing to that volume is incredibly slow at 1.8 MB/s and the CPU usage stays near 0%. There are 8 crpyto/1-8 processes running (it's a Intel Quadcore CPU). I hope that someone on serverfault has seen this before :-(. uname -a 2.6.32-5-xen-amd64 #1 SMP Tue Mar 8 00:01:30 UTC 2011 x86_64 GNU/Linux Interestingly, when I read from the device I get good performance numbers: reading without encryption: $ dd if=/dev/vg0/secure of=/dev/null bs=64k count=100000 100000+0 records in 100000+0 records out 6553600000 bytes (6.6 GB) copied, 68.8951 s, 95.1 MB/s reading with encryption: $ dd if=/dev/mapper/secure of=/dev/null bs=64k count=100000 100000+0 records in 100000+0 records out 6553600000 bytes (6.6 GB) copied, 69.7116 s, 94.0 MB/s However, when I try to write to the device: $ dd if=/dev/zero of=./test bs=64k 8809+0 records in 8809+0 records out 577306624 bytes (577 MB) copied, 321.861 s, 1.8 MB/s Also, when I read I see CPU usage, when I write, the CPU stays at almost 0% usage. Here is output of cryptsetup luksDump: LUKS header information for /dev/vg0/secure Version: 1 Cipher name: aes Cipher mode: cbc-essiv:sha256 Hash spec: sha1 Payload offset: 2056 MK bits: 256 MK digest: dd 62 b9 a5 bf 6c ec 23 36 22 92 4c 39 f8 d6 5d c1 3a b7 37 MK salt: cc 2e b3 d9 fb e3 86 a1 bb ab eb 9d 65 df b3 dd d9 6b f4 49 de 8f 85 7d 3b 1c 90 83 5d b2 87 e2 MK iterations: 44500 UUID: a7c9af61-d9f0-4d3f-b422-dddf16250c33 Key Slot 0: ENABLED Iterations: 178282 Salt: 60 24 cb be 5c 51 9f b4 85 64 3d f8 07 22 54 d4 1a 5f 4c bc 4b 82 76 48 d8 a2 d2 6a ee 13 d7 5d Key material offset: 8 AF stripes: 4000 Key Slot 1: DISABLED Key Slot 2: DISABLED Key Slot 3: DISABLED Key Slot 4: DISABLED Key Slot 5: DISABLED Key Slot 6: DISABLED Key Slot 7: DISABLED

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  • Raid-5 Performance per spindle scaling

    - by Bill N.
    So I am stuck in a corner, I have a storage project that is limited to 24 spindles, and requires heavy random Write (the corresponding read side is purely sequential). Needs every bit of space on my Drives, ~13TB total in a n-1 raid-5, and has to go fast, over 2GB/s sort of fast. The obvious answer is to use a Stripe/Concat (Raid-0/1), or better yet a raid-10 in place of the raid-5, but that is disallowed for reasons beyond my control. So I am here asking for help in getting a sub optimal configuration to be as good as it can be. The array built on direct attached SAS-2 10K rpm drives, backed by a ARECA 18xx series controller with 4GB of cache. 64k array stripes and an 4K stripe aligned XFS File system, with 24 Allocation groups (to avoid some of the penalty for being raid 5). The heart of my question is this: In the same setup with 6 spindles/AG's I see a near disk limited performance on the write, ~100MB/s per spindle, at 12 spindles I see that drop to ~80MB/s and at 24 ~60MB/s. I would expect that with a distributed parity and matched AG's, the performance should scale with the # of spindles, or be worse at small spindle counts, but this array is doing the opposite. What am I missing ? Should Raid-5 performance scale with # of spindles ? Many thanks for your answers and any ideas, input, or guidance. --Bill Edit: Improving RAID performance The other relevant thread I was able to find, discusses some of the same issues in the answers, though it still leaves me with out an answer on the performance scaling.

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  • Mod disk_cache permanent caching images and disabling reacurring header updates

    - by user135532
    I am trying to get mod disk_cache to permantly cache images retrieved from an image server on the webserver using ProxyPass. While the image is being retrieved correctly from the server and is served from the cache on further requests, then I am still having the webserver call the image server and causing the cached header to be updated. Because of load concerns then I need to never call the image server on a specific url again after it has been cached once, or extend the refresh time for as long as possible. The webserver is IHS 7.0 The mod's are mod_disk_cache.so, mod_cache.so, mod_proxy.so Version 2.2.8.0 Following is from my httpd.conf: ProxyPass /webserver/media/images/ http://imageserver.com/ws/media/images/ # Caching pictures <IfModule mod_cache.c> <IfModule mod_disk_cache.c> CacheDefaultExpire 2628000 #CacheDisable CacheEnable disk /webserver/media/images/ CacheIgnoreCacheControl On CacheIgnoreHeaders Cookie Referer User-Agent X-Forwarded-For X-Forwarded-Host X-Forwarded-Server Accept-Language Accept Host CacheIgnoreNoLastMod On CacheIgnoreQueryString Off #CacheIgnoreURLSessionIdentifiers CacheLastModifiedFactor 10000000.1 #CacheLock on #CacheLockMaxAge 5 #CacheLockPath CacheMaxExpire 1576800 CacheStoreNoStore On CacheStorePrivate On CacheDirLength 2 CacheDirLevels 3 CacheMaxFileSize 1000000 CacheMinFileSize 1 CacheRoot c:/cacheroot2 </IfModule> </IfModule>

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  • Why does hiberfil.sys come back from the dead on Windows 7?

    - by Corey White
    I have Windows 7 running on a small (40GB) partition, with 4GB ram. This means that the hiberfil.sys file created by Hibernate takes up a significant portion of the available diskspace. I would like to remove it. I am aware that I can disable Hibernate and remove hiberfil.sys by entering powercfg -h off in an elevated command prompt. This works -- the file is immediately removed, and after doing so, the HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Power\HibernateEnabled key is (correctly) set to 0. However, the next time I reboot the PC, hiberfil.sys returns from the dead, Hibernate is reenabled, and that registry key has returned to 1. I'm pretty much at my wits' end with this. Almost everything I can find online related to removing the hiberfil.sys file simply suggests using powercfg to turn off hibernation, and that appears to work for just about everyone. But it just keeps coming back for me! (Like a vampire, sucking up my disk space.) I did find one other thread from someone who seems to have had the same issue, but none of the suggestions there worked for the original poster (or for me). Still, I have tried everything listed there, including: Disabling hybrid sleep Disabling Hibernate through the command prompt, through the Power Options GUI, and through both (in both orders) Manually changing the HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Power\HibernateEnabled key Pretty much everything else I can think of! I do want to reiterate that I have no problem removing the file -- that works great. It just comes back after every reboot. I'm about ready to throw in the towel and just run a script on login to disable Hibernate each time, even though that seems like a crazily hacky "solution" . . . but I was hoping someone here could suggest something else, first. Thanks!

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  • Slow filesystem access

    - by danneh3826
    I'm trying to diagnose a slow filesystem issue on a server I look after. It's been ongoing for quite some time, and I've run out of ideas as to what I can try. Here's the thick of it. The server itself is a Dell Poweredge T310. It has 4 SAS hard drives in it, configured at RAID5, and is running Citrix XenServer 5.6. The VM is a (relatively) old Debian 5.0.6 installation. It's given 4 cores, and 4Gb's of RAM. It has 3 volumes. A 10Gb volume (ext3) for the system, 980Gb volume (xfs) for data (~94% full), and another 200Gb volume (xfs) for data (~13% full). Now here's the weird thing. Read/write access to the 980Gb volume is really slow. I might get 5Mb/s out of it if I'm lucky. At first I figured it was actually disk access in the system, or at a hypervisor level, but ruled that out entirely as other VMs on the same host are running perfectly fine (a good couple hundred Mb/s disk r/w access). So then I started to target this particular VM. I started thinking it was XFS, but to prove it I wasn't going to attempt to change the filesystem on the 980Gb drive, with years and years of billions of files on there. So I provisioned the 200Gb drive, and did the same read/write test (basically dd), and got a good couple hundred Mb/s r/w access to it. So that ruled out the VM, the hardware, and the filesystem type. There's also a lot of these in /var/log/kern.log; (sorry, this is quite long) Sep 4 10:16:59 uriel kernel: [32571790.564689] httpd: page allocation failure. order:5, mode:0x4020 Sep 4 10:16:59 uriel kernel: [32571790.564693] Pid: 7318, comm: httpd Not tainted 2.6.32-4-686-bigmem #1 Sep 4 10:16:59 uriel kernel: [32571790.564696] Call Trace: Sep 4 10:16:59 uriel kernel: [32571790.564705] [<c1092a4d>] ? __alloc_pages_nodemask+0x476/0x4e0 Sep 4 10:16:59 uriel kernel: [32571790.564711] [<c1092ac3>] ? __get_free_pages+0xc/0x17 Sep 4 10:16:59 uriel kernel: [32571790.564716] [<c10b632e>] ? __kmalloc+0x30/0x128 Sep 4 10:16:59 uriel kernel: [32571790.564722] [<c11dd774>] ? pskb_expand_head+0x4f/0x157 Sep 4 10:16:59 uriel kernel: [32571790.564727] [<c11ddbbf>] ? __pskb_pull_tail+0x41/0x1fb Sep 4 10:16:59 uriel kernel: [32571790.564732] [<c11e4882>] ? dev_queue_xmit+0xe4/0x38e Sep 4 10:16:59 uriel kernel: [32571790.564738] [<c1205902>] ? ip_finish_output+0x0/0x5c Sep 4 10:16:59 uriel kernel: [32571790.564742] [<c12058c7>] ? ip_finish_output2+0x187/0x1c2 Sep 4 10:16:59 uriel kernel: [32571790.564747] [<c1204dc8>] ? ip_local_out+0x15/0x17 Sep 4 10:16:59 uriel kernel: [32571790.564751] [<c12055a9>] ? ip_queue_xmit+0x31e/0x379 Sep 4 10:16:59 uriel kernel: [32571790.564758] [<c1279a90>] ? _spin_lock_bh+0x8/0x1e Sep 4 10:16:59 uriel kernel: [32571790.564767] [<eda15a8d>] ? __nf_ct_refresh_acct+0x66/0xa4 [nf_conntrack] Sep 4 10:16:59 uriel kernel: [32571790.564773] [<c103bf42>] ? _local_bh_enable_ip+0x16/0x6e Sep 4 10:16:59 uriel kernel: [32571790.564779] [<c1214593>] ? tcp_transmit_skb+0x595/0x5cc Sep 4 10:16:59 uriel kernel: [32571790.564785] [<c1005c4f>] ? xen_restore_fl_direct_end+0x0/0x1 Sep 4 10:16:59 uriel kernel: [32571790.564791] [<c12165ea>] ? tcp_write_xmit+0x7a3/0x874 Sep 4 10:16:59 uriel kernel: [32571790.564796] [<c121203a>] ? tcp_ack+0x1611/0x1802 Sep 4 10:16:59 uriel kernel: [32571790.564801] [<c10055ec>] ? xen_force_evtchn_callback+0xc/0x10 Sep 4 10:16:59 uriel kernel: [32571790.564806] [<c121392f>] ? tcp_established_options+0x1d/0x8b Sep 4 10:16:59 uriel kernel: [32571790.564811] [<c1213be4>] ? tcp_current_mss+0x38/0x53 Sep 4 10:16:59 uriel kernel: [32571790.564816] [<c1216701>] ? __tcp_push_pending_frames+0x1e/0x50 Sep 4 10:16:59 uriel kernel: [32571790.564821] [<c1212246>] ? tcp_data_snd_check+0x1b/0xd2 Sep 4 10:16:59 uriel kernel: [32571790.564825] [<c1212de3>] ? tcp_rcv_established+0x5d0/0x626 Sep 4 10:16:59 uriel kernel: [32571790.564831] [<c121902c>] ? tcp_v4_do_rcv+0x15f/0x2cf Sep 4 10:16:59 uriel kernel: [32571790.564835] [<c1219561>] ? tcp_v4_rcv+0x3c5/0x5c0 Sep 4 10:16:59 uriel kernel: [32571790.564841] [<c120197e>] ? ip_local_deliver_finish+0x10c/0x18c Sep 4 10:16:59 uriel kernel: [32571790.564846] [<c12015a4>] ? ip_rcv_finish+0x2c4/0x2d8 Sep 4 10:16:59 uriel kernel: [32571790.564852] [<c11e3b71>] ? netif_receive_skb+0x3bb/0x3d6 Sep 4 10:16:59 uriel kernel: [32571790.564864] [<ed823efc>] ? xennet_poll+0x9b8/0xafc [xen_netfront] Sep 4 10:16:59 uriel kernel: [32571790.564869] [<c11e40ee>] ? net_rx_action+0x96/0x194 Sep 4 10:16:59 uriel kernel: [32571790.564874] [<c103bd4c>] ? __do_softirq+0xaa/0x151 Sep 4 10:16:59 uriel kernel: [32571790.564878] [<c103be24>] ? do_softirq+0x31/0x3c Sep 4 10:16:59 uriel kernel: [32571790.564883] [<c103befa>] ? irq_exit+0x26/0x58 Sep 4 10:16:59 uriel kernel: [32571790.564890] [<c118ff9f>] ? xen_evtchn_do_upcall+0x12c/0x13e Sep 4 10:16:59 uriel kernel: [32571790.564896] [<c1008c3f>] ? xen_do_upcall+0x7/0xc Sep 4 10:16:59 uriel kernel: [32571790.564899] Mem-Info: Sep 4 10:16:59 uriel kernel: [32571790.564902] DMA per-cpu: Sep 4 10:16:59 uriel kernel: [32571790.564905] CPU 0: hi: 0, btch: 1 usd: 0 Sep 4 10:16:59 uriel kernel: [32571790.564908] CPU 1: hi: 0, btch: 1 usd: 0 Sep 4 10:16:59 uriel kernel: [32571790.564911] CPU 2: hi: 0, btch: 1 usd: 0 Sep 4 10:16:59 uriel kernel: [32571790.564914] CPU 3: hi: 0, btch: 1 usd: 0 Sep 4 10:16:59 uriel kernel: [32571790.564916] Normal per-cpu: Sep 4 10:16:59 uriel kernel: [32571790.564919] CPU 0: hi: 186, btch: 31 usd: 175 Sep 4 10:16:59 uriel kernel: [32571790.564922] CPU 1: hi: 186, btch: 31 usd: 165 Sep 4 10:16:59 uriel kernel: [32571790.564925] CPU 2: hi: 186, btch: 31 usd: 30 Sep 4 10:16:59 uriel kernel: [32571790.564928] CPU 3: hi: 186, btch: 31 usd: 140 Sep 4 10:16:59 uriel kernel: [32571790.564931] HighMem per-cpu: Sep 4 10:16:59 uriel kernel: [32571790.564933] CPU 0: hi: 186, btch: 31 usd: 159 Sep 4 10:16:59 uriel kernel: [32571790.564936] CPU 1: hi: 186, btch: 31 usd: 22 Sep 4 10:16:59 uriel kernel: [32571790.564939] CPU 2: hi: 186, btch: 31 usd: 24 Sep 4 10:16:59 uriel kernel: [32571790.564942] CPU 3: hi: 186, btch: 31 usd: 13 Sep 4 10:16:59 uriel kernel: [32571790.564947] active_anon:485974 inactive_anon:121138 isolated_anon:0 Sep 4 10:16:59 uriel kernel: [32571790.564948] active_file:75215 inactive_file:79510 isolated_file:0 Sep 4 10:16:59 uriel kernel: [32571790.564949] unevictable:0 dirty:516 writeback:15 unstable:0 Sep 4 10:16:59 uriel kernel: [32571790.564950] free:230770 slab_reclaimable:36661 slab_unreclaimable:21249 Sep 4 10:16:59 uriel kernel: [32571790.564952] mapped:20016 shmem:29450 pagetables:5600 bounce:0 Sep 4 10:16:59 uriel kernel: [32571790.564958] DMA free:2884kB min:72kB low:88kB high:108kB active_anon:0kB inactive_anon:0kB active_file:5692kB inactive_file:724kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15872kB mlocked:0kB dirty:8kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:5112kB slab_unreclaimable:156kB kernel_stack:56kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no Sep 4 10:16:59 uriel kernel: [32571790.564964] lowmem_reserve[]: 0 698 4143 4143 Sep 4 10:16:59 uriel kernel: [32571790.564977] Normal free:143468kB min:3344kB low:4180kB high:5016kB active_anon:56kB inactive_anon:2068kB active_file:131812kB inactive_file:131728kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:715256kB mlocked:0kB dirty:156kB writeback:0kB mapped:308kB shmem:4kB slab_reclaimable:141532kB slab_unreclaimable:84840kB kernel_stack:1928kB pagetables:22400kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no Sep 4 10:16:59 uriel kernel: [32571790.564983] lowmem_reserve[]: 0 0 27559 27559 Sep 4 10:16:59 uriel kernel: [32571790.564995] HighMem free:776728kB min:512kB low:4636kB high:8760kB active_anon:1943840kB inactive_anon:482484kB active_file:163356kB inactive_file:185588kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:3527556kB mlocked:0kB dirty:1900kB writeback:60kB mapped:79756kB shmem:117796kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no Sep 4 10:16:59 uriel kernel: [32571790.565001] lowmem_reserve[]: 0 0 0 0 Sep 4 10:16:59 uriel kernel: [32571790.565011] DMA: 385*4kB 16*8kB 3*16kB 9*32kB 6*64kB 2*128kB 1*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 2900kB Sep 4 10:16:59 uriel kernel: [32571790.565032] Normal: 21505*4kB 6508*8kB 273*16kB 24*32kB 3*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 143412kB Sep 4 10:16:59 uriel kernel: [32571790.565054] HighMem: 949*4kB 8859*8kB 7063*16kB 6186*32kB 4631*64kB 727*128kB 6*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 776604kB Sep 4 10:16:59 uriel kernel: [32571790.565076] 198980 total pagecache pages Sep 4 10:16:59 uriel kernel: [32571790.565079] 14850 pages in swap cache Sep 4 10:16:59 uriel kernel: [32571790.565082] Swap cache stats: add 2556273, delete 2541423, find 82961339/83153719 Sep 4 10:16:59 uriel kernel: [32571790.565085] Free swap = 250592kB Sep 4 10:16:59 uriel kernel: [32571790.565087] Total swap = 385520kB Sep 4 10:16:59 uriel kernel: [32571790.575454] 1073152 pages RAM Sep 4 10:16:59 uriel kernel: [32571790.575458] 888834 pages HighMem Sep 4 10:16:59 uriel kernel: [32571790.575461] 11344 pages reserved Sep 4 10:16:59 uriel kernel: [32571790.575463] 1090481 pages shared Sep 4 10:16:59 uriel kernel: [32571790.575465] 737188 pages non-shared Now, I've no idea what this means. There's plenty of free memory; total used free shared buffers cached Mem: 4247232 3455904 791328 0 5348 736412 -/+ buffers/cache: 2714144 1533088 Swap: 385520 131004 254516 Though now I see the swap is relatively low in size, but would that matter? I've been starting to think about fragmentation, or inode usage on that large partition, but a recent fsck on it showed is as only like 0.5% fragmented. Which leaves me with inode usage, but how much of an effect really would a large inode table or filesystem TOC have? I've love to hear people's opinions on this. It's driving me potty! df -h output; Filesystem Size Used Avail Use% Mounted on /dev/xvda1 9.5G 6.6G 2.4G 74% / tmpfs 2.1G 0 2.1G 0% /lib/init/rw udev 10M 520K 9.5M 6% /dev tmpfs 2.1G 0 2.1G 0% /dev/shm /dev/xvdb 980G 921G 59G 94% /data

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  • Reading and writing C++ vector to a file

    - by JB
    For some graphics work I need to read in a large amount of data as quickly as possible and would ideally like to directly read and write the data structures to disk. Basically I have a load of 3d models in various file formats which take too long to load so I want to write them out in their "prepared" format as a cache that will load much faster on subsequent runs of the program. Is it safe to do it like this? My worries are around directly reading into the data of the vector? I've removed error checking, hard coded 4 as the size of the int and so on so that i can give a short working example, I know it's bad code, my question really is if it is safe in c++ to read a whole array of structures directly into a vector like this? I believe it to be so, but c++ has so many traps and undefined behavour when you start going low level and dealing directly with raw memory like this. I realise that number formats and sizes may change across platforms and compilers but this will only even be read and written by the same compiler program to cache data that may be needed on a later run of the same program. #include <fstream> #include <vector> using namespace std; struct Vertex { float x, y, z; }; typedef vector<Vertex> VertexList; int main() { // Create a list for testing VertexList list; Vertex v1 = {1.0f, 2.0f, 3.0f}; list.push_back(v1); Vertex v2 = {2.0f, 100.0f, 3.0f}; list.push_back(v2); Vertex v3 = {3.0f, 200.0f, 3.0f}; list.push_back(v3); Vertex v4 = {4.0f, 300.0f, 3.0f}; list.push_back(v4); // Write out a list to a disk file ofstream os ("data.dat", ios::binary); int size1 = list.size(); os.write((const char*)&size1, 4); os.write((const char*)&list[0], size1 * sizeof(Vertex)); os.close(); // Read it back in VertexList list2; ifstream is("data.dat", ios::binary); int size2; is.read((char*)&size2, 4); list2.resize(size2); // Is it safe to read a whole array of structures directly into the vector? is.read((char*)&list2[0], size2 * sizeof(Vertex)); }

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  • Missing drive space in Server 2003

    - by Tim Brigham
    I have two drives used for SQL backups which for the last week have been acting strange - the free space indicated by windows is far off from what windirstat, etc indicates. There should only be about 60 GB of drive space used and there is about 160. This would match the utilization if the two last backup files were still residing on disk. SQL server is 2000, OS Server 2003 x64. Running on a VMware 5.0 cluster. OSSEC and McAfee for this system shows clean. My current plan is to temporarily attach one of these drives this drive to another VM for analysis. Is there anything more I should be looking at? There were a lot of pages on the net when I was looking for documentation on this issue but I haven't found this case described. EDIT: Unfortunately even a full reboot did not clear this behavior. I also used process explorer to look for open file handles. No dice.

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