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  • How would I force Debian to use the physical sector size on a hard disk?

    - by Confused User
    I just purchased a few new 3TB WD drives. These have physical 4k sectors, but there is some sort of layer which is providing 512B logical sectors (see the partition table below). In order to attempt to get some more speed out of my hard drives, I would like to get rid of this logical layer and actually use the physical 4k sectors. However, I can't figure out how to do this (or even if it's possible) from the man pages of fdisk and parted, or from searching Google. Does anybody know how this could be done? As to why this is relevant, this page demonstrates that meerly aligning the sectors properly can already make up to a 25% speed difference for reads, and more than 2500% for writes in some cases! Getting rid of the logical sectors in favor of the physicals ones should improve speeds even more. Thanks! $ parted /dev/sdc GNU Parted 2.3 Using /dev/sdc Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print Model: ATA WDC WD30EZRX-00M (scsi) Disk /dev/sdc: 3001GB Sector size (logical/physical): 512B/4096B Partition Table: gpt Number Start End Size File system Name Flags 1 1049kB 3001GB 3001GB zfs 9 3001GB 3001GB 8389kB P.S. I don't care about the data on the drives, I was just playing with different file systems. Also, this is my first time posting here, so please let me know if my posts should be formatted differently, etc.

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  • All of the NTFS hard links disappear, where are hardlinks stored on disk and how to recover them?

    - by Osiris
    This is Windows 7 x64 sp1 on a NTFS file system. All hardlinks within C:\Windows\System32 folder disappear, and the Windows can't boot, because even the osloader, C:\Windows\System32\boot\Winload.exe also disappeared. Nevertheless, the original files are still located in the corresponding C:\Windows\winsxs folders. After booting into the Recovery Environment, and copied one Winload.exe (x64) from other folder, Windows gave an error pointing out that "ntoskrnl.exe is corrupted or missing...its file digital signature cannot be verified" In trying to boot in Safe Mode, the message above was shown after a screen prompting "Loaded \Windows\system32\config\system" Because at this early booting stage, smss.exe was still not loaded, so there is not any dumping and logs. Based on my study, ntoskrnl.exe depends on the following files: C:\\windows\\system32\\PSHED.DLL C:\\Windows\\System32\\hal.dll C:\\Windows\\System32\\kdcom.dll C:\\Windows\\System32\\clfs.sys C:\\Windows\\System32\\ci.dll All those files above are copied from their corresponding folders and verified their md5 with a well-operating Windows 7 x64 SP1. But the booting error is still the same: "ntoskrnl.exe is corrupted or missing..." **Background:** Before the reboot, there was an windows update going on. Then something unknown happen, almost all processes were broken to run, including the windows task manager, taskmgr.exe. After mount the hard disk to other computer, it seems that all hardlinks within C:\Windows\System32 folder were gone. I tried several data recovery software, but they are not be able to find those disappeared NTFS hard links. So the question is: Where are information about those hard links stored? And how to recover them? Are they depend on some windows service or stored in the registry?

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  • How can I access user files on a disk moved from a Windows 7 machine to an XP machine?

    - by Fantius
    I moved the hard drive from one machine (Win 7) to another (XP) and now certain folders tell me "Access denied". I am logged in as an administrator. I had a different account on the other machine. Neither account authenticated to anything besides the local machine. The old machine is apparently dead, so I can't do anything in there like change permissions, etc. How can I access these files? Edit: After changing the ownerships of all the files and folders on the drive, I am getting a different error. And it is troubling me deeply. "xxx refers to a location that is unavailable. It could be on a hard drive on this computer, or on a network. Check to make sure that the disk is properly inserted, or that you are connected to the Internet or your network, and then try again. If it still cannot be located, the information might have been moved to a different location." No change after rebooting. Any ideas? Surely the files are still there, right?

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  • Why does lighttpd keep static files in cache, even when modified on disk ?

    - by Pixelastic
    I am using lighttpd to serve static files. I have a bunch of images in a dir that I regularly update. This will change the file content (and filesize) as well as the modification date, but not their filename. When I access the files through http, the updates are not taken into account and lighty serves the old file. I can manually rename the file to something different, then lighttpd will return a 404 error, and if I rename my file back, I will get the correct updated version. Seems like lightty is using some kind of cache mechanism of its own (which is fine) to return static files. Unfortunatly, it seems that this mechanism doesn't update itself when files are modified. I checked through Wireshark, and my browser is really doing a request to the file, this is not a browser caching issue. It returns a 200 OK when requesting it from an empty cache, and a 304 Not Modified otherwise, as expected. But the file is returned with a wrong Last-Modified header that do not reflect the real last modification date. Maybe there is some config directive that I am not aware of ? I would like the files returned by lighty to reflect the changes made on disk directly, or at least being able to invalidate its cache.

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  • How do I prevent lighttpd from caching static files, even when modified on disk?

    - by Pixelastic
    I am using lighttpd to serve static files. I have a bunch of images in a dir that I regularly update. This will change the file content (and filesize) as well as the modification date, but not their filename. When I access the files through http, the updates are not taken into account and lighty serves the old file. I can manually rename the file to something different, then lighttpd will return a 404 error, and if I rename my file back, I will get the correct updated version. Seems like lightty is using some kind of cache mechanism of its own (which is fine) to return static files. Unfortunatly, it seems that this mechanism doesn't update itself when files are modified. I checked through Wireshark, and my browser is really doing a request to the file, this is not a browser caching issue. It returns a 200 OK when requesting it from an empty cache, and a 304 Not Modified otherwise, as expected. But the file is returned with a wrong Last-Modified header that do not reflect the real last modification date. Maybe there is some config directive that I am not aware of ? I would like the files returned by lighty to reflect the changes made on disk directly, or at least being able to invalidate its cache.

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  • VMWare-Mount not recognizing virtual disks

    - by user36175
    I have two disks as .vmdk files, and four as .vdi files. I can boot virtual machines on them with Sun xMV VirtualBox, and they work just fine. However, I want to mount them on my local computer so I can read some files off of them without starting a virtual machine. I downloaded the vmware-mount utility, but I get this error, even when mounting .vmdk files, which should be VMWare images... Unable to mount the virtual disk. The disk may be in use by a virtual machine, may not have enough volumes or mounted under another drive letter. If not, verify that the file is a valid virtual disk file. Thinking it's a problem with the utility, I downloaded the SDK and made my own simple program in C to try to mount a disk. It just initializes the API, connects to it, then attempts to open the disk. I get this error, once again claiming it is not a virtual disk: **LOG: DISKLIB-DSCPTR: descriptor above max size: I64u **LOG: DISKLIB-LINK : "f:\programming\VMs\windowstrash.vdi" : failed to open (The file specified is not a virtual disk). **LOG: DISKLIB-CHAIN : "f:\programming\VMs\windowstrash.vdi" : failed to open (The file specified is not a virtual disk). **LOG: DISKLIB-LIB : Failed to open 'f:\programming\VMs\windowstrash.vdi' with flags 0x1e (The file specified is not a virtual disk). ** FAILURE ** : The file specified is not a virtual disk The files are clearly virtual disks, though, since I can actually mount and use them with a virtual machine. I tried detaching them from any VMs and trying again, but I got the same results. Any ideas? Maybe the "descriptor above max size" is a hint? Some more info: the .vmdk disks were created on other computers. I just copied them to mine and created new VMs around them, but they work fine. All the .vdi files were created on my machine. Not sure if that affects anything. Update: WinMount can mount the file.. so the problem seems to be with vmware-mount.

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  • How to repair an external harddrive?

    - by dodohjk
    I would like to reformat my hard disk, and if possible recover the (somewhat unimportant) contents if possible. I have a Western Digital 1TB hard drive which had a NTFS partition. I unplugged the drive without safely removing it first. At first a pop up was asking me to use a Windows OS to run the chkdsk /f command, however, in the effort to keep using a Linux OS I used the ntfsfix command on the ubuntu terminal Now, when I try to access the hard drive, it doesn't show up anymore in Nautilus. I tried reformatting it using Disk Utility, but it gives me an error message, and Gparted would hang on the "Scanning devices" step infinitely. Please comment any output that you would like to see and I will add it to my question. EDIT disk utility tells me is on /dev/sdb the command sudo fdisk -l gives dodohjk@DodosPC:~$ sudo fdisk -l [sudo] password for dodohjk: Disk /dev/sda: 250.1 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders, total 488397168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0006fa8c Device Boot Start End Blocks Id System /dev/sda1 * 4094 482344959 241170433 5 Extended /dev/sda2 482344960 488396799 3025920 82 Linux swap / Solaris /dev/sda5 4096 31461127 15728516 83 Linux /dev/sda6 31463424 52434943 10485760 83 Linux /dev/sda7 52436992 62923320 5243164+ 83 Linux /dev/sda8 62924800 482344959 209710080 83 Linux Disk /dev/sdb: 1000.2 GB, 1000202043392 bytes 255 heads, 63 sectors/track, 121600 cylinders, total 1953519616 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x6e697373 This doesn't look like a partition table Probably you selected the wrong device. Device Boot Start End Blocks Id System /dev/sdb1 ? 1936269394 3772285809 918008208 4f QNX4.x 3rd part /dev/sdb2 ? 1917848077 2462285169 272218546+ 73 Unknown /dev/sdb3 ? 1818575915 2362751050 272087568 2b Unknown /dev/sdb4 ? 2844524554 2844579527 27487 61 SpeedStor Partition table entries are not in disk order I wrote something wrong here, however here the output of fsck /dev/sbd is dodohjk@DodosPC:~$ sudo fsck /dev/sdb fsck from util-linux 2.20.1 e2fsck 1.42.5 (29-Jul-2012) ext2fs_open2: Bad magic number in super-block fsck.ext2: Superblock invalid, trying backup blocks... fsck.ext2: Bad magic number in super-block while trying to open /dev/sdb The superblock could not be read or does not describe a correct ext2 filesystem. If the device is valid and it really contains an ext2 filesystem (and not swap or ufs or something else), then the superblock is corrupt, and you might try running e2fsck with an alternate superblock: e2fsck -b 8193 <device&gt;

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  • howto plan RAID for ESX

    - by maruti
    eight 300GB SAS drives are available. Can ESX be put on one disk as RAID-0 and others as RAID-5 ? so that in the event of disk failure data (VMs) are safe. if os disk RAID-0 fails could that be installed on replacement disk and still be able to keep VMs running? if not RAID-1 for OS is only option for OS disk? please suggest any other RAID options.

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  • SAS Expanders vs Direct Attached (SAS)?

    - by jemmille
    I have a storage unit with 2 backplanes. One backplane holds 24 disks, one backplane holds 12 disks. Each backplane is independently connected to a SFF-8087 port (4 channel/12Gbit) to the raid card. Here is where my question really comes in. Can or how easily can a backplane be overloaded? All the disks in the machine are WD RE4 WD1003FBYX (black) drives that have average writes at 115MB/sec and average read of 125 MB/sec I know things would vary based on the raid or filesystem we put on top of that but it seems to be that a 24 disk backplane with only one SFF-8087 connector should be able to overload the bus to a point that might actually slow it down? Based on my math, if I had a RAID0 across all 24 disks and asked for a large file, I should, in theory should get 24*115 MB/sec wich translates to 22.08 GBit/sec of total throughput. Either I'm confused or this backplane is horribly designed, at least in a perfomance environment. I'm looking at switching to a model where each drive has it's own channel from the backplane (and new HBA's or raid card). EDIT: more details We have used both pure linux (centos), open solaris, software raid, hardware raid, EXT3/4, ZFS. Here are some examples using bonnie++ 4 Disk RAID-0, ZFS WRITE CPU RE-WRITE CPU READ CPU RND-SEEKS 194MB/s 19% 92MB/s 11% 200MB/s 8% 310/sec 194MB/s 19% 93MB/s 11% 201MB/s 8% 312/sec --------- ---- --------- ---- --------- ---- --------- 389MB/s 19% 186MB/s 11% 402MB/s 8% 311/sec 8 Disk RAID-0, ZFS WRITE CPU RE-WRITE CPU READ CPU RND-SEEKS 324MB/s 32% 164MB/s 19% 346MB/s 13% 466/sec 324MB/s 32% 164MB/s 19% 348MB/s 14% 465/sec --------- ---- --------- ---- --------- ---- --------- 648MB/s 32% 328MB/s 19% 694MB/s 13% 465/sec 12 Disk RAID-0, ZFS WRITE CPU RE-WRITE CPU READ CPU RND-SEEKS 377MB/s 38% 191MB/s 22% 429MB/s 17% 537/sec 376MB/s 38% 191MB/s 22% 427MB/s 17% 546/sec --------- ---- --------- ---- --------- ---- --------- 753MB/s 38% 382MB/s 22% 857MB/s 17% 541/sec Now 16 Disk RAID-0, it's gets interesting WRITE CPU RE-WRITE CPU READ CPU RND-SEEKS 359MB/s 34% 186MB/s 22% 407MB/s 18% 1397/sec 358MB/s 33% 186MB/s 22% 407MB/s 18% 1340/sec --------- ---- --------- ---- --------- ---- --------- 717MB/s 33% 373MB/s 22% 814MB/s 18% 1368/sec 20 Disk RAID-0, ZFS WRITE CPU RE-WRITE CPU READ CPU RND-SEEKS 371MB/s 37% 188MB/s 22% 450MB/s 19% 775/sec 370MB/s 37% 188MB/s 22% 447MB/s 19% 797/sec --------- ---- --------- ---- --------- ---- --------- 741MB/s 37% 376MB/s 22% 898MB/s 19% 786/sec 24 Disk RAID-1, ZFS WRITE CPU RE-WRITE CPU READ CPU RND-SEEKS 347MB/s 34% 193MB/s 22% 447MB/s 19% 907/sec 347MB/s 34% 192MB/s 23% 446MB/s 19% 933/sec --------- ---- --------- ---- --------- ---- --------- 694MB/s 34% 386MB/s 22% 894MB/s 19% 920/sec 28 Disk RAID-0, ZFS 32 Disk RAID-0, ZFS 36 Disk RAID-0, ZFS More details: Here is the exact unit: http://www.supermicro.com/products/chassis/4U/847/SC847E1-R1400U.cfm

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  • Impossible to create/format install window 7 on unpartioned HD

    - by fra pet
    Hi guys i am getting nut reinstalling windows 7 on one of those Acer aspire all-in-one... The original OS(windows professional x64) was not starting, after the initial screen the bios was prompted. So step 1: i tried to access the system partition and reinstall everything but could not get at the point step 2: i set the bios to native ide and i tried to insert my original copy of windows professional and do a clean installation, but it does not allow me to format/create other partion form the installation mask step 3: my BAD, i tried to install ubuntu and i clean the whole hard drive, i was getting an error at some point during installation so i decided to get back to windows step 4: Windows 7 again, at the disk screen of the windows installation i entered into the prompt and played around with DISKPART... -i listed the disk and the HD was disk 0. -i selected disk 0. -i CLEAN disk 0 successfully. -i tried to create a CREATE PARTITION PRIMARY but gave an error cache corrupt and disk not up-to-date (after i try to create a partiton in disk 0 it disappear when i try LIST DISK and i have to restart before he can list DISK 0 again, RESCAN did not worked). -tried CLEAN ALL(2 hours) and succeeded. -try again to create primary partition and failed, same errors -try to install my old copy of windows xP pro and it seems to work, it create a partition, format(only quick worked, slow mode was at 0% after 1 hour so i stop), it start installing and around 90% installation said it could not copy a file and he stop -back on windows 7 again, it says that the hard drive has 490+gb unpartitioned but won't create a partition and format. -i tried again DISKPART as i though i messed up with the MBR when i installed ubuntu, so i did all of the instruction below http://www.sevenforums.com/tutorials/20864-mbr-restore-windows-7-master-boot-record.html http://support.microsoft.com/kb/927392 the errors were: on bootsect: the systne partiton was not found, Data error cyclic redundancy check on bootrec /FixMbr: A device attached to the system is not functioning but did not worked, and still can not partiton/format/install on a blank HD i tried some bootable clean disk tool and start infinite loop on the same errors the bios setting are: sata: native ide. if i put AHCL(or something like that does not load the HD and the DVD). quick start/quite start: disabled. Are there any other option or tools i can try before i try change the HD(That is my last option)? Thanks to everyone.

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  • Why do I bother with RAID 10 ?

    - by GrumpyOldDBA
    Before I post anything I just want to clarify what I mean by RAID 10 , this is sets of mirrored pairs that have been striped as against a RAID 0 which has been mirrored. I've just had a disk failure in the data array for one of my dev servers, it's an eight disk raid 8, no real worries, replace disk and off we go - but no - the HP engineers told me from the diagnostics ( done to ensure I got the right replacement under warranty ) that not only had a disk failed but I'd lost all the data...(read more)

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  • Ubuntu 11.10 doesn't detect external usb hard drive

    - by Andrew
    I have been batting with this issue for a bit and cannot find the answer to it. So the Dmesg see's the device, being Symwave WDC WD64.... media@Media-pc:~$ dmesg | tail -n 20 [78678.719497] scsi 10:0:0:0: Direct-Access Generic- USB3.0 CRW -0 1.00 PQ: 0 ANSI: 0 CCS [78678.725621] scsi 10:0:0:1: Direct-Access Generic- USB3.0 CRW -1 1.00 PQ: 0 ANSI: 0 CCS [78684.073837] scsi 11:0:0:0: Direct-Access SYMWAVE WDC WD6400AAKS-0 3B01 PQ: 0 ANSI: 4 [78691.008126] scsi 11:0:0:0: uas_eh_abort_handler tag 0 [78691.008139] scsi 11:0:0:0: uas_eh_device_reset_handler tag 0 [78691.008147] scsi 11:0:0:0: uas_eh_target_reset_handler tag 0 [78691.008154] scsi 11:0:0:0: uas_eh_bus_reset_handler tag 0 [78691.080307] usb 2-2.4: reset high speed USB device number 9 using ehci_hcd [78691.221427] scsi 11:0:0:0: Device offlined - not ready after error recovery [78691.221498] scsi 11:0:0:0: rejecting I/O to offline device [78691.221519] scsi 11:0:0:0: rejecting I/O to offline device [78691.222952] scsi 11:0:0:1: Enclosure SYMWAVE SES 3B01 PQ: 0 ANSI: 4 [78691.223156] scsi 11:0:0:2: uas_sense_old: urb length 26 disagrees with IU sense data length 510, using 18 bytes of sense data [78691.225061] sd 11:0:0:0: Attached scsi generic sg3 type 0 [78691.225344] ses 11:0:0:1: Attached Enclosure device [78691.225495] ses 11:0:0:1: Attached scsi generic sg4 type 13 [78691.226266] sd 10:0:0:0: Attached scsi generic sg5 type 0 [78691.226653] sd 10:0:0:1: Attached scsi generic sg6 type 0 [78691.241647] sd 10:0:0:0: [sdd] Attached SCSI removable disk [78691.243832] sd 10:0:0:1: [sde] Attached SCSI removable disk It looks like it attaches sdd and sde. Now when i look in the disk utility it shows "Hard disk Symwave WD6400AAKS-0 device /dev/sdc doesn't show any other info then that, if i format, it says that it cannot open /dev/sdc no device or address error. Underneeth the device it does show two general usb3.0 CRW that are sdd and sde. Now if I do a fdisk -l it doesn't show the device: media@Media-pc:~$ sudo fdisk -l Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000247de Device Boot Start End Blocks Id System /dev/sda1 * 2048 152176639 76087296 83 Linux /dev/sda2 152178686 156301311 2061313 5 Extended /dev/sda5 152178688 156301311 2061312 82 Linux swap / Solaris Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x948fc822 Device Boot Start End Blocks Id System /dev/sdb1 63 1953520064 976760001 7 HPFS/NTFS/exFAT So now I am confused. Any ideas how I get fdisk to see the device?

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  • Unable to boot from LiveCD/USB and even Super Grub Disk!

    - by Reuben L.
    Hi all, I'm in a fix. Basically this morning, I decided to format my Win7 as it was getting really slow and I did so with no problems. I also have a Linux Mint OS on dual boot. Since I was springcleaning my windows partition, I decided it was a good idea to do the same to my linux partition. I downloaded the latest version of Linux Mint (Julia) and burned the LiveCD. Now here is where the problem lies, when I restarted Windows and chose to boot from the LiveCD, it didn't work. No joke. There was just a little underscore blinking for a long time before it went back to GRUB which prompted me to select an OS to boot. However, when I went into my old Linux Mint OS and restarted the machine, the LiveCD worked... to a certain extent. It would load and look as though it was ready to install Linux Mint 10 but the moment it got to the option screen, the whole screen turned into a checkered and jumbled mess. At this point I thought it was the LiveCD or the .iso file. I had an Ubuntu LiveUSB for recovery purposes and I tried that. The exact same thing happened. Can't boot the LiveUSB if I restarted from Windows, but works when I reboot from Linux. BUT still the same checkered screen that doesnt respond. Did a bit of googling and reckoned it might be something wrong with my GRUB. Did some updating and didnt make a difference. Then I tried the Super Grub Disk and STUPIDLY uninstalled GRUB. (Note that booting to SGD had the exact same problem - can't be done if I rebooted from Windows). Now I can't access my Linux Mint 9 cos the the bootup screen (mbr) only has Windows 7 as an option. Remember me mentioning that I can't boot from any CD/USB/recovery CD when I reboot from Windows? And now that I can't access Linux, there's no way for me to do any form of recovery! I've tried using the command prompt utility at startup recovery but to no avail. Anyone can help me with this?

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  • Can't install any Linux distro

    - by rstreeter78
    I have been trying to install Ubuntu on my step-son's netbook and I checked and his hard disk seems to be failing and i keep getting an error message that Ubuntu is unable to install due to hard disk failure. I was wondering how and if it is possible to install Ubuntu on this hard disk without it giving me an error message. I have tried the alternate install disk image and the regular desktop image and get basically the same error message. Is there a way to somehow override this and get it installed

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  • How do you re-mount an ext3 fs readwrite after it gets mounted readonly from a disk error?

    - by cagenut
    Its a relatively common problem when something goes wrong in a SAN for ext3 to detect the disk write errors and remount the filesystem read-only. Thats all well and good, only when the SAN is fixed I can't figure out how to re-re-mount the filesystem read-write without rebooting. Behold: [root@localhost ~]# multipath -ll mpath0 (36001f93000a310000299000200000000) dm-2 XIOTECH,ISE1400 [size=1.1T][features=1 queue_if_no_path][hwhandler=0][rw] \_ round-robin 0 [prio=2][active] \_ 1:0:0:1 sdb 8:16 [active][ready] \_ 2:0:0:1 sdc 8:32 [active][ready] [root@localhost ~]# mount /dev/mapper/mpath0 /mnt/foo [root@localhost ~]# touch /mnt/foo/blah All good, now I yank the LUN out from under it. [root@localhost ~]# touch /mnt/foo/blah [root@localhost ~]# touch /mnt/foo/blah touch: cannot touch `/mnt/foo/blah': Read-only file system [root@localhost ~]# tail /var/log/messages Mar 18 13:17:33 localhost multipathd: sdb: tur checker reports path is down Mar 18 13:17:34 localhost multipathd: sdc: tur checker reports path is down Mar 18 13:17:35 localhost kernel: Aborting journal on device dm-2. Mar 18 13:17:35 localhost kernel: Buffer I/O error on device dm-2, logical block 1545 Mar 18 13:17:35 localhost kernel: lost page write due to I/O error on dm-2 Mar 18 13:17:36 localhost kernel: ext3_abort called. Mar 18 13:17:36 localhost kernel: EXT3-fs error (device dm-2): ext3_journal_start_sb: Detected aborted journal Mar 18 13:17:36 localhost kernel: Remounting filesystem read-only It only thinks its read-only, in reality its not even there. [root@localhost ~]# multipath -ll sdb: checker msg is "tur checker reports path is down" sdc: checker msg is "tur checker reports path is down" mpath0 (36001f93000a310000299000200000000) dm-2 XIOTECH,ISE1400 [size=1.1T][features=0][hwhandler=0][rw] \_ round-robin 0 [prio=0][enabled] \_ 1:0:0:1 sdb 8:16 [failed][faulty] \_ 2:0:0:1 sdc 8:32 [failed][faulty] [root@localhost ~]# ll /mnt/foo/ ls: reading directory /mnt/foo/: Input/output error total 20 -rw-r--r-- 1 root root 0 Mar 18 13:11 bar How it still remembers that 'bar' file being there... mystery, but not important right now. Now I re-present the LUN: [root@localhost ~]# tail /var/log/messages Mar 18 13:23:58 localhost multipathd: sdb: tur checker reports path is up Mar 18 13:23:58 localhost multipathd: 8:16: reinstated Mar 18 13:23:58 localhost multipathd: mpath0: queue_if_no_path enabled Mar 18 13:23:58 localhost multipathd: mpath0: Recovered to normal mode Mar 18 13:23:58 localhost multipathd: mpath0: remaining active paths: 1 Mar 18 13:23:58 localhost multipathd: dm-2: add map (uevent) Mar 18 13:23:58 localhost multipathd: dm-2: devmap already registered Mar 18 13:23:59 localhost multipathd: sdc: tur checker reports path is up Mar 18 13:23:59 localhost multipathd: 8:32: reinstated Mar 18 13:23:59 localhost multipathd: mpath0: remaining active paths: 2 Mar 18 13:23:59 localhost multipathd: dm-2: add map (uevent) Mar 18 13:23:59 localhost multipathd: dm-2: devmap already registered [root@localhost ~]# multipath -ll mpath0 (36001f93000a310000299000200000000) dm-2 XIOTECH,ISE1400 [size=1.1T][features=1 queue_if_no_path][hwhandler=0][rw] \_ round-robin 0 [prio=2][enabled] \_ 1:0:0:1 sdb 8:16 [active][ready] \_ 2:0:0:1 sdc 8:32 [active][ready] Great right? It says [rw] right there. Not so fast: [root@localhost ~]# touch /mnt/foo/blah touch: cannot touch `/mnt/foo/blah': Read-only file system OK, doesn't do it automatically, I'll just give it a little push: [root@localhost ~]# mount -o remount /mnt/foo mount: block device /dev/mapper/mpath0 is write-protected, mounting read-only Noooooooooo. I have tried all sorts of different mount/tune2fs/dmsetup commands and I cannot figure out how to get it to un-flag the block device as write-protected. Rebooting will fix it, but I'd much rather do it on-line. An hour of googling has gotten me nowhere either. Save me ServerFault.

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  • How do you re-mount an ext3 fs readwrite after it gets mounted readonly from a disk error?

    - by cagenut
    Its a relatively common problem when something goes wrong in a SAN for ext3 to detect the disk write errors and remount the filesystem read-only. Thats all well and good, only when the SAN is fixed I can't figure out how to re-re-mount the filesystem read-write without rebooting. Behold: [root@localhost ~]# multipath -ll mpath0 (36001f93000a310000299000200000000) dm-2 XIOTECH,ISE1400 [size=1.1T][features=1 queue_if_no_path][hwhandler=0][rw] \_ round-robin 0 [prio=2][active] \_ 1:0:0:1 sdb 8:16 [active][ready] \_ 2:0:0:1 sdc 8:32 [active][ready] [root@localhost ~]# mount /dev/mapper/mpath0 /mnt/foo [root@localhost ~]# touch /mnt/foo/blah All good, now I yank the LUN out from under it. [root@localhost ~]# touch /mnt/foo/blah [root@localhost ~]# touch /mnt/foo/blah touch: cannot touch `/mnt/foo/blah': Read-only file system [root@localhost ~]# tail /var/log/messages Mar 18 13:17:33 localhost multipathd: sdb: tur checker reports path is down Mar 18 13:17:34 localhost multipathd: sdc: tur checker reports path is down Mar 18 13:17:35 localhost kernel: Aborting journal on device dm-2. Mar 18 13:17:35 localhost kernel: Buffer I/O error on device dm-2, logical block 1545 Mar 18 13:17:35 localhost kernel: lost page write due to I/O error on dm-2 Mar 18 13:17:36 localhost kernel: ext3_abort called. Mar 18 13:17:36 localhost kernel: EXT3-fs error (device dm-2): ext3_journal_start_sb: Detected aborted journal Mar 18 13:17:36 localhost kernel: Remounting filesystem read-only It only thinks its read-only, in reality its not even there. [root@localhost ~]# multipath -ll sdb: checker msg is "tur checker reports path is down" sdc: checker msg is "tur checker reports path is down" mpath0 (36001f93000a310000299000200000000) dm-2 XIOTECH,ISE1400 [size=1.1T][features=0][hwhandler=0][rw] \_ round-robin 0 [prio=0][enabled] \_ 1:0:0:1 sdb 8:16 [failed][faulty] \_ 2:0:0:1 sdc 8:32 [failed][faulty] [root@localhost ~]# ll /mnt/foo/ ls: reading directory /mnt/foo/: Input/output error total 20 -rw-r--r-- 1 root root 0 Mar 18 13:11 bar How it still remembers that 'bar' file being there... mystery, but not important right now. Now I re-present the LUN: [root@localhost ~]# tail /var/log/messages Mar 18 13:23:58 localhost multipathd: sdb: tur checker reports path is up Mar 18 13:23:58 localhost multipathd: 8:16: reinstated Mar 18 13:23:58 localhost multipathd: mpath0: queue_if_no_path enabled Mar 18 13:23:58 localhost multipathd: mpath0: Recovered to normal mode Mar 18 13:23:58 localhost multipathd: mpath0: remaining active paths: 1 Mar 18 13:23:58 localhost multipathd: dm-2: add map (uevent) Mar 18 13:23:58 localhost multipathd: dm-2: devmap already registered Mar 18 13:23:59 localhost multipathd: sdc: tur checker reports path is up Mar 18 13:23:59 localhost multipathd: 8:32: reinstated Mar 18 13:23:59 localhost multipathd: mpath0: remaining active paths: 2 Mar 18 13:23:59 localhost multipathd: dm-2: add map (uevent) Mar 18 13:23:59 localhost multipathd: dm-2: devmap already registered [root@localhost ~]# multipath -ll mpath0 (36001f93000a310000299000200000000) dm-2 XIOTECH,ISE1400 [size=1.1T][features=1 queue_if_no_path][hwhandler=0][rw] \_ round-robin 0 [prio=2][enabled] \_ 1:0:0:1 sdb 8:16 [active][ready] \_ 2:0:0:1 sdc 8:32 [active][ready] Great right? It says [rw] right there. Not so fast: [root@localhost ~]# touch /mnt/foo/blah touch: cannot touch `/mnt/foo/blah': Read-only file system OK, doesn't do it automatically, I'll just give it a little push: [root@localhost ~]# mount -o remount /mnt/foo mount: block device /dev/mapper/mpath0 is write-protected, mounting read-only The hell you are: [root@localhost ~]# mount -o remount,rw /mnt/foo mount: block device /dev/mapper/mpath0 is write-protected, mounting read-only Noooooooooo. I have tried all sorts of different mount/tune2fs/dmsetup commands and I cannot figure out how to get it to un-flag the block device as write-protected. Rebooting will fix it, but I'd much rather do it on-line. An hour of googling has gotten me nowhere either. Save me ServerFault.

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  • OS Missing? Messed up the MBR on Win7 64-bit

    - by hom3lesshom3boy
    I have a Windows 7 machine with two hard drives: a 1TB C: drive and 500GB J:. I had Windows XP installed on C: and Windows 7 installed on J:. I installed Windows 7 after Windows XP from an installer .exe I (legally) bought and downloaded. It, and all of my other files, are sitting on my J: drive intact. While under my Windows 7 install, a few days ago I decided to use Priform's CCleaner and use its DriveWipe utility to wipe the C: drive. 1% into the process, I cancelled and attempted to use it again. It gives me an error saying it can't format the drive, so I poke around the Internet a bit, give up, and restart my computer. I first get an "OS is missing" error after the computer boots past the BIOS. I downloaded and put UBCD on a bootable USB to use another drivewiping tool to completely erase the C: drive, hoping it'll take the problem with it. No luck. I try to use TestDisk to make my J: my primary active drive, but no luck. I still get the "OS is missing" error. Or sometimes it'll hang at Verifying DMI Pool. Or sometimes I'll get the "NTLDR is missing" error. I get hold of Hiren's and put it on another bootable USB. I first I tried the Boot Windows 7 from Hard Drive option, and I get "Error 15: File Not Found". I tried the "Fix 'NTLDR is Missing'" option (I'm not quite sure why this is even showing up, since I'm trying to get into a HDD with Windows 7 installed. Probably messed up somewhere when I used TestDisk) and I get this list: I'll run through the error messages I get: 1st Try - Windows could not start because the following file is missing or corrupt: \system32\hal.dll 2nd Try - Windows could not start because the following file is missing or corrupt: \system32\ntoskrnl.exe 3rd Try - Windows could not start because of a computer disk hardware configuration problem. Could not read from the selected boot disk. Check boot path and disk hardware. 4th - 8th Try - Same as #3 9th Try - I/O Error accessing boot sector file multi(0)disk(0)fdisk(0)\BOOTSEC.DOS. And computer freezes. 10th Try - computer restarts Needless to say, not a single one of those works. I then tried to open up the Windows 7 exe I have sitting on my J: from the Mini-XP OS on Hiren's, but it won't run because I'm trying to run a 64-bit file from a 32-bit exe. At least, that's the problem according to these guys: http://social.technet.microsoft.com/...-b2f54e9c7d18/ I then borrowed a 64-bit Windows Home Premium CD from a friend to get to the recovery options. But I get the error message: This version of System Recovery Options is not compatible with the version of Windows you are trying to repair. Try using a recovery disc that is compatible with this version of Windows. I pressed Shift + F10 to get to the Command Prompt directly. These are the exact steps I took from there (paraphrased a little): X:\Sources>bootrec /Fixmbr The operation completed successfully. X:\Sources>bootrec /Fixboot The operation completed successfully. I restarted my computer, but it still didn't work. I unplugged the C: drive, then tried bootrec and Diskpart: X:\Sources> bootrec.exe X:\Sources> bootrec /RebuildBcd Total identified Windows installations: 1 [1] \\?\GLOBALROOT\Device\HarddiskVolume1\Windows Add installation to bootlist? Yes(Y)/No(N)/All(A):y The requested system device cannot be found. X:\Sources>DiskPart DISKPART> List Disk Disk # Status Size Free Dyn Gpt Disk 0_Online_465GB_0B_______* Disk 1 Online 1000MB 0B (this is Hiren's on a bootable usb) DISKPART> Select Disk 0 Disk 0 is now the selected disk. DISKPART> List Partition Partition # Type Size Offset Partition 1 System 465GB 31KB DISKPART> Select Partition 1 Partition 1 is now the selected partition DISKPART> Active The selected disk is not a fixed MBR disk. The ACTIVE command can only be used on fixed MBR disks. DISKPART> exit Leaving Diskpart... X:\Sources>bootrec /Fixmbr The operation completed successfully. X:\Sources>bootrec /Fixboot The operation completed successfully. Before I go any further, is there anything I'm overlooking/doing wrong? All I care about is making the J: and Windows 7 bootable again. SPECS: Windows 7 Professional 64-Bit GIGABYTE - Motherboard - Socket 775 - GA-P35-DS3R (rev. 2.1) Crucial Ballistix 2048MB PC6400 DDR2 800MHz (2x2GB) Intel Core 2 Duo E6700 Processor (2.6 (6GHZ) I think... not sure anymore C: HDD - SAMSUNG HD103UJ (1TB, not plugged in) J: HDD - WDC WD5000AKS-00V1A0 (500GB)

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  • e2fsck extremly slow, although enough memory exists

    - by kaefert
    I've got this external USB-Disk: kaefert@blechmobil:~$ lsusb -s 2:3 Bus 002 Device 003: ID 0bc2:3320 Seagate RSS LLC As can be seen in this dmesg output, there are some problems that prevents that disk from beeing mounted: kaefert@blechmobil:~$ dmesg | grep sdb [ 114.474342] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.475089] sd 5:0:0:0: [sdb] Write Protect is off [ 114.475092] sd 5:0:0:0: [sdb] Mode Sense: 43 00 00 00 [ 114.475959] sd 5:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 114.477093] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.501649] sdb: sdb1 [ 114.502717] sd 5:0:0:0: [sdb] 732566645 4096-byte logical blocks: (3.00 TB/2.72 TiB) [ 114.504354] sd 5:0:0:0: [sdb] Attached SCSI disk [ 116.804408] EXT4-fs (sdb1): ext4_check_descriptors: Checksum for group 3976 failed (47397!=61519) [ 116.804413] EXT4-fs (sdb1): group descriptors corrupted! So I went and fired up my favorite partition manager - gparted, and told it to verify and repair the partition sdb1. This made gparted call e2fsck (version 1.42.4 (12-Jun-2012)) e2fsck -f -y -v /dev/sdb1 Although gparted called e2fsck with the "-v" option, sadly it doesn't show me the output of my e2fsck process (bugreport https://bugzilla.gnome.org/show_bug.cgi?id=467925 ) I started this whole thing on Sunday (2012-11-04_2200) evening, so about 48 hours ago, this is what htop says about it now (2012-11-06-1900): PID USER PRI NI VIRT RES SHR S CPU% MEM% TIME+ Command 3704 root 39 19 1560M 1166M 768 R 98.0 19.5 42h56:43 e2fsck -f -y -v /dev/sdb1 Now I found a few posts on the internet that discuss e2fsck running slow, for example: http://gparted-forum.surf4.info/viewtopic.php?id=13613 where they write that its a good idea to see if the disk is just that slow because maybe its damaged, and I think these outputs tell me that this is not the case in my case: kaefert@blechmobil:~$ sudo hdparm -tT /dev/sdb /dev/sdb: Timing cached reads: 3562 MB in 2.00 seconds = 1783.29 MB/sec Timing buffered disk reads: 82 MB in 3.01 seconds = 27.26 MB/sec kaefert@blechmobil:~$ sudo hdparm /dev/sdb /dev/sdb: multcount = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 364801/255/63, sectors = 5860533160, start = 0 However, although I can read quickly from that disk, this disk speed doesn't seem to be used by e2fsck, considering tools like gkrellm or iotop or this: kaefert@blechmobil:~$ iostat -x Linux 3.2.0-2-amd64 (blechmobil) 2012-11-06 _x86_64_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 14,24 47,81 14,63 0,95 0,00 22,37 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sda 0,59 8,29 2,42 5,14 43,17 160,17 53,75 0,30 39,80 8,72 54,42 3,95 2,99 sdb 137,54 5,48 9,23 0,20 587,07 22,73 129,35 0,07 7,70 7,51 16,18 2,17 2,04 Now I researched a little bit on how to find out what e2fsck is doing with all that processor time, and I found the tool strace, which gives me this: kaefert@blechmobil:~$ sudo strace -p3704 lseek(4, 41026998272, SEEK_SET) = 41026998272 write(4, "\212\354K[_\361\3nl\212\245\352\255jR\303\354\312Yv\334p\253r\217\265\3567\325\257\3766"..., 4096) = 4096 lseek(4, 48404766720, SEEK_SET) = 48404766720 read(4, "\7t\260\366\346\337\304\210\33\267j\35\377'\31f\372\252\ffU\317.y\211\360\36\240c\30`\34"..., 4096) = 4096 lseek(4, 41027002368, SEEK_SET) = 41027002368 write(4, "\232]7Ws\321\352\t\1@[+5\263\334\276{\343zZx\352\21\316`1\271[\202\350R`"..., 4096) = 4096 lseek(4, 48404770816, SEEK_SET) = 48404770816 read(4, "\17\362r\230\327\25\346//\210H\v\311\3237\323K\304\306\361a\223\311\324\272?\213\tq \370\24"..., 4096) = 4096 lseek(4, 41027006464, SEEK_SET) = 41027006464 write(4, "\367yy>x\216?=\324Z\305\351\376&\25\244\210\271\22\306}\276\237\370(\214\205G\262\360\257#"..., 4096) = 4096 lseek(4, 48404774912, SEEK_SET) = 48404774912 read(4, "\365\25\0\21|T\0\21}3t_\272\373\222k\r\177\303\1\201\261\221$\261B\232\3142\21U\316"..., 4096) = 4096 ^CProcess 3704 detached around 16 of these lines every second, so 4 read and 4 write operations every second, which I don't consider to be a lot.. And finally, my question: Will this process ever finish? If those numbers from fseek (48404774912) represent bytes, that would be something like 45 gigabytes, with this beeing a 3 terrabyte disk, which would give me 134 days to go, if the speed stays constant, and he scans the disk like this completly and only once. Do you have some advice for me? I have most of the data on that disk elsewhere, but I've put a lot of hours into sorting and merging it to this disk, so I would prefer to getting this disk up and running again, without formatting it anew. I don't think that the hardware is damaged since the disk is only a few months and since I can't see any I/O errors in the dmesg output. UPDATE: I just looked at the strace output again (2012-11-06_2300), now it looks like this: lseek(4, 1419860611072, SEEK_SET) = 1419860611072 read(4, "3#\f\2447\335\0\22A\355\374\276j\204'\207|\217V|\23\245[\7VP\251\242\276\207\317:"..., 4096) = 4096 lseek(4, 43018145792, SEEK_SET) = 43018145792 write(4, "]\206\231\342Y\204-2I\362\242\344\6R\205\361\324\177\265\317C\334V\324\260\334\275t=\10F."..., 4096) = 4096 lseek(4, 1419860615168, SEEK_SET) = 1419860615168 read(4, "\262\305\314Y\367\37x\326\245\226\226\320N\333$s\34\204\311\222\7\315\236\336\300TK\337\264\236\211n"..., 4096) = 4096 lseek(4, 43018149888, SEEK_SET) = 43018149888 write(4, "\271\224m\311\224\25!I\376\16;\377\0\223H\25Yd\201Y\342\r\203\271\24eG<\202{\373V"..., 4096) = 4096 lseek(4, 1419860619264, SEEK_SET) = 1419860619264 read(4, ";d\360\177\n\346\253\210\222|\250\352T\335M\33\260\320\261\7g\222P\344H?t\240\20\2548\310"..., 4096) = 4096 lseek(4, 43018153984, SEEK_SET) = 43018153984 write(4, "\360\252j\317\310\251G\227\335{\214`\341\267\31Y\202\360\v\374\307oq\3063\217Z\223\313\36D\211"..., 4096) = 4096 So this number of the lseeks before the reads, like 1419860619264 are already a lot bigger, standing for 1.29 terabytes if the numbers are bytes, so it doesn't seem to be a linear progress on a big scale, maybe there are only some areas that need work, that have big gaps in between them. (times are in CET)

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  • Why Are Minimized Programs Often Slow to Open Again?

    - by Jason Fitzpatrick
    It seems particularly counterintuitive: you minimize an application because you plan on returning to it later and wish to skip shutting the application down and restarting it later, but sometimes maximizing it takes even longer than launching it fresh. What gives? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Bart wants to know why he’s not saving any time with application minimization: I’m working in Photoshop CS6 and multiple browsers a lot. I’m not using them all at once, so sometimes some applications are minimized to taskbar for hours or days. The problem is, when I try to maximize them from the taskbar – it sometimes takes longer than starting them! Especially Photoshop feels really weird for many seconds after finally showing up, it’s slow, unresponsive and even sometimes totally freezes for minute or two. It’s not a hardware problem as it’s been like that since always on all on my PCs. Would I also notice it after upgrading my HDD to SDD and adding RAM (my main PC holds 4 GB currently)? Could guys with powerful pcs / macs tell me – does it also happen to you? I guess OSes somehow “focus” on active software and move all the resources away from the ones that run, but are not used. Is it possible to somehow set RAM / CPU / HDD priorities or something, for let’s say, Photoshop, so it won’t slow down after long period of inactivity? So what is the deal? Why does he find himself waiting to maximize a minimized app? The Answer SuperUser contributor Allquixotic explains why: Summary The immediate problem is that the programs that you have minimized are being paged out to the “page file” on your hard disk. This symptom can be improved by installing a Solid State Disk (SSD), adding more RAM to your system, reducing the number of programs you have open, or upgrading to a newer system architecture (for instance, Ivy Bridge or Haswell). Out of these options, adding more RAM is generally the most effective solution. Explanation The default behavior of Windows is to give active applications priority over inactive applications for having a spot in RAM. When there’s significant memory pressure (meaning the system doesn’t have a lot of free RAM if it were to let every program have all the RAM it wants), it starts putting minimized programs into the page file, which means it writes out their contents from RAM to disk, and then makes that area of RAM free. That free RAM helps programs you’re actively using — say, your web browser — run faster, because if they need to claim a new segment of RAM (like when you open a new tab), they can do so. This “free” RAM is also used as page cache, which means that when active programs attempt to read data on your hard disk, that data might be cached in RAM, which prevents your hard disk from being accessed to get that data. By using the majority of your RAM for page cache, and swapping out unused programs to disk, Windows is trying to improve responsiveness of the program(s) you are actively using, by making RAM available to them, and caching the files they access in RAM instead of the hard disk. The downside of this behavior is that minimized programs can take a while to have their contents copied from the page file, on disk, back into RAM. The time increases the larger the program’s footprint in memory. This is why you experience that delay when maximizing Photoshop. RAM is many times faster than a hard disk (depending on the specific hardware, it can be up to several orders of magnitude). An SSD is considerably faster than a hard disk, but it is still slower than RAM by orders of magnitude. Having your page file on an SSD will help, but it will also wear out the SSD more quickly than usual if your page file is heavily utilized due to RAM pressure. Remedies Here is an explanation of the available remedies, and their general effectiveness: Installing more RAM: This is the recommended path. If your system does not support more RAM than you already have installed, you will need to upgrade more of your system: possibly your motherboard, CPU, chassis, power supply, etc. depending on how old it is. If it’s a laptop, chances are you’ll have to buy an entire new laptop that supports more installed RAM. When you install more RAM, you reduce memory pressure, which reduces use of the page file, which is a good thing all around. You also make available more RAM for page cache, which will make all programs that access the hard disk run faster. As of Q4 2013, my personal recommendation is that you have at least 8 GB of RAM for a desktop or laptop whose purpose is anything more complex than web browsing and email. That means photo editing, video editing/viewing, playing computer games, audio editing or recording, programming / development, etc. all should have at least 8 GB of RAM, if not more. Run fewer programs at a time: This will only work if the programs you are running do not use a lot of memory on their own. Unfortunately, Adobe Creative Suite products such as Photoshop CS6 are known for using an enormous amount of memory. This also limits your multitasking ability. It’s a temporary, free remedy, but it can be an inconvenience to close down your web browser or Word every time you start Photoshop, for instance. This also wouldn’t stop Photoshop from being swapped when minimizing it, so it really isn’t a very effective solution. It only helps in some specific situations. Install an SSD: If your page file is on an SSD, the SSD’s improved speed compared to a hard disk will result in generally improved performance when the page file has to be read from or written to. Be aware that SSDs are not designed to withstand a very frequent and constant random stream of writes; they can only be written over a limited number of times before they start to break down. Heavy use of a page file is not a particularly good workload for an SSD. You should install an SSD in combination with a large amount of RAM if you want maximum performance while preserving the longevity of the SSD. Use a newer system architecture: Depending on the age of your system, you may be using an out of date system architecture. The “system architecture” is generally defined as the “generation” (think generations like children, parents, grandparents, etc.) of the motherboard and CPU. Newer generations generally support faster I/O (input/output), better memory bandwidth, lower latency, and less contention over shared resources, instead providing dedicated links between components. For example, starting with the “Nehalem” generation (around 2009), the Front-Side Bus (FSB) was eliminated, which removed a common bottleneck, because almost all system components had to share the same FSB for transmitting data. This was replaced with a “point to point” architecture, meaning that each component gets its own dedicated “lane” to the CPU, which continues to be improved every few years with new generations. You will generally see a more significant improvement in overall system performance depending on the “gap” between your computer’s architecture and the latest one available. For example, a Pentium 4 architecture from 2004 is going to see a much more significant improvement upgrading to “Haswell” (the latest as of Q4 2013) than a “Sandy Bridge” architecture from ~2010. Links Related questions: How to reduce disk thrashing (paging)? Windows Swap (Page File): Enable or Disable? Also, just in case you’re considering it, you really shouldn’t disable the page file, as this will only make matters worse; see here. And, in case you needed extra convincing to leave the Windows Page File alone, see here and here. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

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  • I need to write a program that reads angles in radians from an input disk and converts them in degre

    - by Amadou
    Write a program that reads angles in radians from an input disk le and converts them into degrees, minutes, and seconds. Output should be written into another le. A sample input le could be: # this is a comment # your program should be able to skip comment lines # and blank lines # input radian numbers could be seperated by blanks 0.0 1.0 # or by a newline 3.141593 6.0

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  • Is it possible to gzip and upload this string to Amazon S3 without ever being written to disk?

    - by BigJoe714
    I know this is probably possible using Streams, but I wasn't sure the correct syntax. I would like to pass a string to the Save method and have it gzip the string and upload it to Amazon S3 without ever being written to disk. The current method inefficiently reads/writes to disk in between. The S3 PutObjectRequest has a constructor with InputStream input as an option. import java.io.*; import java.util.zip.GZIPOutputStream; import com.amazonaws.auth.PropertiesCredentials; import com.amazonaws.services.s3.AmazonS3; import com.amazonaws.services.s3.AmazonS3Client; import com.amazonaws.services.s3.model.PutObjectRequest; public class FileStore { public static void Save(String data) throws IOException { File file = File.createTempFile("filemaster-", ".htm"); file.deleteOnExit(); Writer writer = new OutputStreamWriter(new FileOutputStream(file)); writer.write(data); writer.flush(); writer.close(); String zippedFilename = gzipFile(file.getAbsolutePath()); File zippedFile = new File(zippedFilename); zippedFile.deleteOnExit(); AmazonS3 s3 = new AmazonS3Client(new PropertiesCredentials( new FileInputStream("AwsCredentials.properties"))); String bucketName = "mybucket"; String key = "test/" + zippedFile.getName(); s3.putObject(new PutObjectRequest(bucketName, key, zippedFile)); } public static String gzipFile(String filename) throws IOException { try { // Create the GZIP output stream String outFilename = filename + ".gz"; GZIPOutputStream out = new GZIPOutputStream(new FileOutputStream(outFilename)); // Open the input file FileInputStream in = new FileInputStream(filename); // Transfer bytes from the input file to the GZIP output stream byte[] buf = new byte[1024]; int len; while ((len = in.read(buf)) > 0) { out.write(buf, 0, len); } in.close(); // Complete the GZIP file out.finish(); out.close(); return outFilename; } catch (IOException e) { throw e; } } }

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