• mdadm how to stop a check


    Is a mdadm check on your trusty software RAID array happening at the worst time and slowing down your server or NAS? cat /proc/mdstat Personalities : [raid1] [raid10] md127 : active raid10 sdb4[0] sda4[1] 897500672 blocks super 1.2 2 near-copies [2/2] [UU] [==========>..........] check = 50.4% (452485504/897500672) finish=15500.3min speed=478K/sec ........
  • OpenVZ vs LXC DIR mode poor security in LXC


    It is unfortunate that LXC's dir mode is completely insecure and allows way too much information from the host to be seen. I wonder if there will eventually be a way to break into the host filesystem or other container's storage? OpenVZ better security: [root@ev ~]# cat /proc/mdstat cat: /proc/mdstat: No such file or directory /dev/simfs 843G 740G 61G........
  • mdadm force resync when resync=PENDING solution


    cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] md127 : active (auto-read-only) raid10 sdc1[0] sdb1[2] 1953382400 blocks super 1.2 512K chunks 2 far-copies [2/1] [U_] resync=PENDING bitmap: 15/15 pages [60KB], 65536KB chunk Solution force repai........
  • What happens when you unplug 1 or more devices from an mdadm RAID array to simulate a failure in Linux Ubuntu/Centos/Debian?


    In short the two drives in the array were /dev/sdd and /dev/sde. The kernel sees they were unplugged and have gone down as you can see below. mdadm caught the first one being unplugged /dev/sde and disabled the missing drive. However when the final drive that was part of the array is unplugged it didn't notice at all. Instead it complains about an IO error later for drives that the kernel knows do not exist anymore. [45817.162728] ata4: exception........
  • Centos 6 how to guide convert LVM non-RAID into mdadm 1/10 RAID array live without reinstalling


    Here is the scenario you or a client have a remote machine that was installed as a standard/default minimal Centos 6.x machine on a single disk with LVM for whatever reason. Often many people do not know how to install it to a RAID array so it is common to have this problem and why reinstall if you don't need to? In some cases on a remote system you can't easily reinstall without physical or KVM access. So in this case you add a second physical or disk or already ha........
  • What a hdd hard drive and mdadm RAID array failure looks like in Linux


    [3805108.257042] sd 0:0:0:0: [sda] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB) [3805108.257052] sd 0:0:0:0: [sda] Write Protect is off [3805108.257054] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [3805108.257066] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [3805108.257083] sd 0:0:0:0: [sda] 1953525168 512-byte hardware sectors: (1.00 TB/931 GiB) [3805108.257090] sd 0:0:0:0: [sda] Write Protect is off........
  • mdadm create RAID 1 array example


    mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3 cat /proc/mdstat Personalities : [raid1] md2 : active raid1 sdb3[1] sda3[0] 1363020736 blocks super 1.2 [2/2] [UU] [=>...................] resync = 8.3% (113597440/1363020736) finish=276.2min speed=75366K/sec ........
  • mdadm recover from dead drive


    mdadm --manage /dev/md3 --add /dev/sda1 cat /proc/mdstat Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5] [raid4] [raid10] md0 : inactive sdd2[1] sdd1[2](S) 31270272 blocks md3 : active raid1 sda1[2] sdb1[1] sdc1[3](F) 943730240 blocks [2/1] [_U] [>....................]........
  • mdadm/md-check how to check array integrity without rebuilding


    This doesn't seem to be widely known (maybe it's in some documentation that none of us read though)but there's an easy way to check the integrity of any mdadm array: sudo echo check > /sys/block/md0/md/sync_action -bash: /sys/block/md0/md/sync_action: Permission denied sudo will never work, this only works as root since echo is not actually a binary/command. It is built-into bash. /sys/devices/virtu........
  • md: data-check of RAID array md3


    This really made me nervous but notice the mdstat says "check". This is because in Ubuntu there is a scheduled mdadm cronscript that runs everyday on Sunday at 00:57 that checks your entire array. This is a good way because it prevents gradual but unnoticed data corruption which Inever thought of. As long as the check completes properly you have peace of mind knowing that your data integretiy is assured and that your hard drives are functioning properly (I'........
  • mdadm RAID 1 adventures


    I separated the 2 drives in the RAID 1 array. 1 is the old one /dev/sda and is out of date, while the separated other one /dev/sdc was in another drive and mounted and used with more data (updated). I wonder how mdadm will handle this: usb-storage: device scan complete md: md127 stopped. md: bind md: md127: raid array is not clean -- starting background reconstruction raid1: raid set md127 active with 1 out of 2 m........
  • mdadm Linux Software RAID QuickStart Guide


    Create New RAID 1 Array: First setup your partitions (make sure they are exactly the same size) In my example I have sda3 and sdb3 which are 500GB in size. mdadm --create /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3 mdadm: array /dev/md2 started. Check Status Of The Array *Note I already have other arrays md0 and md1. You can see below that md2 is syn........
  • mdadm "auto-read-only" Linux Software RAID solution


    If you have the "(auto-read-only)" beside an arrayI have no idea why that happens but it is easy to fix. Just run "mdadm --readwrite /dev/md1" (rename md0 to the device with the problem and it will begin to resync. md1 : active (auto-read-only) raid1 sdb2[0] sda2[1] 19534976 blocks [2/2] [UU] resync=PENDING ........
  • mdadm Linux Software RAID auto-detect and assemble RAID Array


    mdadm --assemble --scan mdadm: /dev/md/diaghost05102010:2 has been started with 2 drives. mdadm: /dev/md/diaghost05102010:1 has been started with 2 drives. mdadm: /dev/md/diaghost05102010:0 has been started with 2 drives. -bash-3.1# cat /proc/mdstat Personalities : [linear] [raid0] [raid1] [raid6] [raid5] [raid4] [multipath] md125 : active raid1 sda1[0] sdb1[1] 14658185 blocks super 1.2........
  • Convert HDD/Hard Drive Partition(s) into non-RAID into RAID 1 using existing data without data loss and without reformatting.


    Before we start I take no responsibility for this, you should have a backup and if you make a mistake during this process you could wipe out all of your data. So backup somewhere else before starting this as a precaution, or make sure it's data you could afford to lose. The RAID 1 Setup (Hardware Wise) I've already setup my 2 x 1TB (Seagate) drives with identical partitions, make sure your new hard drive (the empty one) is setup like your curr........
  • Latest Articles

  • Aruba/HP/Dell IAP Wireless Controller Common Default Passwords
  • Debian, Mint Ubuntu how to remove package and associated config files
  • Linux Grub not booting the intended kernel solution in Debian, Mint, Ubuntu how to specify which kernel to boot by default
  • QEMU KVM Keyboard Problems Not Working Right Repeating Characters, Ctrl+C Copy and Paste not working right when using PS2 mouse in guests Solution
  • Linux how to compile binary with static sharedobjects embedded instead of dynamic to use on multi-distributions and avoid glibc compatiblity issues
  • /bin/sh: msgfmt: not found error solution on Linux Compilation Ubuntu Debian Mint Centos
  • Mikrotik RouterOS CHR/ISO Basic and Quick Setup Howto Guide
  • qemu 4 compilation options
  • CentOS 7 8 PXEBoot Netinstall Not Working Solution "Pane is dead "new value non-exisetnt xfs filesystem is not valid as a default fs type"
  • CentOS 6 EOL yum repo won't work Error: Cannot find a valid baseurl for repo: base Solution
  • CentOS 7 8 How To Disable SELinux
  • Wordpress How To Add Featured Image To Post in Hueman Theme
  • kdenlive full reset how to erase all config files
  • CentOS 7 8 yum error Trying other mirror. To address this issue please refer to the below wiki article
  • Microsoft Teams Linux - Calendar Doesn't Work Missed Meetings!
  • Scanner not working in Linux Ubuntu Fedora Mint Debian over the network? Use sane-airscan!
  • How To Boot, Install and Run Windows 2000 on QEMU-KVM
  • bash cannot execute permission denied
  • Huion and Wacom Tablets How To Install in Linux Mint / Ubuntu and make the stylus work properly
  • ffmpeg how to cut certain parts of video out