SnapRAID Plugin Guide

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    • SnapRAID Plugin Guide

      How to setup SnapRAID in OMV


      This Tutorial shows how to install and configure SnapRAID on your OMV-machine.

      Requirements Plugin

      RAID is no Backup!
      Repeat after me three times: RAID is not backup. Period.
      Backup your data:…ackup-day-the-3-2-1-rule/

      Why SnapRAID and not RAID5?

      I have many large mediafiles on my HDDs which doesn't change so often. If a mediafile is read, then only one HDD has to spin up in SnapRAID instead of all HDDs in a RAID5. Another reason for SnapRAID is you can use it with already filled HDDs. Compare SnapRAID with other solutions:

      Install openmediavault-snapraid im OMV > System > Plugins
      If you can't see the plugin, please have a look above at "Requirements"

      Explanation of terms:
      is for the snapraid.content files. The list of files is saved in the "content" files, usually stored in the data, parity or boot disks.

      SnapRAID Manual wrote:

      The list of files is saved in the "content" files, usually stored in the data, parity or boot disks. These files contain the details of your backup, with all the checksums to verify its integrity. The "content" file is stored in multiple copies, and each one must be in a different disk, to ensure that in even in case of multiple disk failures at least one copy is available.

      is the label for your data-drives, where your data (movies, music etc.) is.


      is the parity-drive in SnapRAID. These disks will be dedicated to store the "parity" files. You should not store your data in them.

      SnapRAID Manual wrote:

      As parity disks, you have to pick the biggest disks in the array, as the parity information may grow in size as the biggest data disk in the array.

      Please have a look at the SnapRAID-Manual also. See the "more info" section at the end of this Tutorial.

      Change your settings in OpenMediaVault -> SnapRAID

      1. add Data-Drives
      Click on ""Add", choose your datadrive and give it a name, just for SnapRAID. If you use short names it is easier to handle. I've chosen alma, berta, ... but you can also use d1 for the first disk, d2 for the second ...
      BTW: I put a small label on the HDD in my Server to know which disk it is.
      Then choose, if you also want to store a "content"-file on the disk. Content files are necessary to restore files. I added a "content-file" on every data-disk to make sure i
      have enough copies. You need at least "Paritydrives+1" copies of the content. If you have only one Parity-Drive, then you need at least 2 copies of the content-file. So having them on every Datadisk is more than secure. In my setup the content file is only 378MB.

      2. Add a disk for the parityfile.
      The Parity-drive has to be equal or bigger than the biggest datadrive to have enough space for the parity-file.
      I'm using the parity-drive just for parity, there is some space left, but it's already filled 95% with parity-file.

      - in- or exclude some files
      I'm using Kodi, so I excluded some files

      • For directories you must use the ending slash, e.g exclude /Users/ will exclude every Users-directory, exclude /User/ (without the ending slash) will exclude every file named "Users"
      • It is not possible to exclude a specific \Users\ directory on drive XY. The filters are applied equally to all disks.
      • Filters are relative to the mount point /media/your-uuid-here-1234-5678. The sample above /Users/ will exclude every Users dir in the main-root of the HDD: e.g. /media/your-uuid-here-1234-5678/Users/
      • Have a look at Section 8 in the SnapRAID manual for more info
      Make sure, you change the settings to fit your needs.

      - read more about the commands
      with the "Info"-Tab you can see, what the buttons are doing

      - finally, you can control your snapraid.conf file, if you want
      With the "Config"-Tab you can view the SnapRAID-config written by OMV

      First run
      Now you are ready to sync your data the first time. Click on the "Sync"-Button

      you get a output like this: (yours is maybe a little bit different)

      Source Code

      1. Self test...
      2. Loading state from /media/926fb5ca-b54e-4dfc-xxxx-4c25ad072265/.content...
      3. warning: Content file '/media/926fb5ca-b54e-4dfc-xxxx-4c25ad072265/.content' not found, trying with another copy...
      4. Loading state from /media/f607a0b8-0539-495f-xxxx-1b722f63db69/.content...
      5. warning: Content file '/media/f607a0b8-0539-495f-xxxx-1b722f63db69/.content' not found, trying with another copy...
      6. Loading state from /media/08afa682-defa-47fe-xxxx-147ccaf164d4/.content...
      7. warning: Content file '/media/08afa682-defa-47fe-xxxx-147ccaf164d4/.content' not found, trying with another copy...
      8. Loading state from /media/336ce995-52bf-4f88-xxxx-37a4a8797bf4/.content...
      9. warning: No content file found. Assuming empty.
      10. Scanning disk f607a0b8-0539-495f-xxxx-1b722f63db69-alma...
      11. Scanning disk 926fb5ca-b54e-4dfc-xxxx-4c25ad072265-berta...
      12. Scanning disk 08afa682-defa-47fe-xxxx-147ccaf164d4-serina...
      13. Scanning disk 336ce995-52bf-4f88-xxxx-37a4a8797bf4-highdy...
      14. Using 1124 MiB of memory.
      15. Saving state to /media/926fb5ca-b54e-4dfc-xxxx-4c25ad072265/.content...
      16. Saving state to /media/f607a0b8-0539-495f-xxxx-1b722f63db69/.content...
      17. Saving state to /media/08afa682-defa-47fe-xxxx-147ccaf164d4/.content...
      18. Saving state to /media/336ce995-52bf-4f88-xxxx-37a4a8797bf4/.content...
      19. Initializing...
      20. Syncing...
      Display All

      For my 4 2TB-HDDs this was done after about 20 hours. Now your Data is safe.

      Show modified files:

      If you add or delete files after the last sync, you can click on "Diff" to see the deleted, added or moved files. To update and protect your new data, click on "Sync" again.

      A HDD is defect, what now?
      edit/change the entry in omv-snapraid from the old HDD to the new one.

      Source Code

      1. snapraid -d name_of_the_defective_Disk -l /path/to/logfile fix

      a sample output is this:

      Source Code

      1. Self test...
      2. Loading state from /var/snapraid/content...
      3. UUID change for disk alma' from 'f607a0b8-0539-495f-xxxx-1b722f63db69' to '3cdb119b-e2c5-xxxx-b19d-30fe82182e27'
      4. Filtering...
      5. Initializing...
      6. Fixing...
      7. 7%, 321506 MB, 84 MB/s, 12:40 ETA

      After that, your data is restored on the new HDD.

      More info:

      Questions / Problems / Diskussions

      Click here to get to the diskussions thread

      Thanks Solo for the Guide!

      version: 0.3
      - change pics to reflect the GUI changes in omv-snapraid 1.x
      version: 0.4
      - added include/exclude info

      version: 0.5
      - added "Explanation of terms": data, content, parity

      version: 0.6
      - added "RAID is no backup"

      The post was edited 7 times, last by Solo0815 ().