How to Setup Snapraid

    • OMV 4.x

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    • How to Setup Snapraid

      Hi, newbie here, wondering about the process for setting up snapraid and it's best practices...I have one box with OMV and a vanilla Raid 5, but seems that the snapraid might be better for my needs, which is basically archiving photography and video allowing for common access for two people as designer and photographer. Long periods of inactivity, infrequent access, but easier to access and organize file as opposed to multiple drives separate...
      Any suggestions for a good how to would be appreciated....

      Thnks...oh by the way, is it true what they say about raid five being destined to fail?
    • Here's a link to the basic -> setup.

      Things to remember:
      You want at least 2 content files, set on two different data drives. (An intact content file is necessary for a restore.)
      The Parity drive must be the same size as, or larger, than the largest drive in the array.
      While the link references UnionFS (some call it MergerFS), it's not necessary to setup SNAPRAID.
      _____________________________________________________

      There's lots of reasons why RAID5 is becoming harder to justify as time goes on.
      - The write hole (easy to counter - use an UPS)
      - It wasn't designed for today's stupendous sized drives.
      - Rebuilds are taking so long (again huge drives where rebuilds may take days) that the rebuild operation itself can cause additional drive failures.
      (With RAID5, two drive failures and it's over.)
      ____________________________________________________

      Since you seem to be using your server as part of a business, make sure you have real backup (in addition to SNAPRAID). A large external drive, at a minimum, is a very good idea.

      The post was edited 1 time, last by crashtest ().

    • thanks for the advice...for future reference, what may be the preferred method to go from raid five to snapraid?
      1. new omv install, setup snapraid, erasing existing raid, populate with backups....
      2. new omv install, setup snapraid using exsting raid five disks Will new snapraid recognize and use the old raid five in any way?

      Post by crashtest ().

      This post was deleted by the author themselves: Dup ().
    • mneese wrote:

      thanks for the advice...for future reference, what may be the preferred method to go from raid five to snapraid?
      1. new omv install, setup snapraid, erasing existing raid, populate with backups....
      2. new omv install, setup snapraid using exsting raid five disks Will new snapraid recognize and use the old raid five in any way?

      1. Yes. Format each individual drive and it you want a "RAID like" array, UnionFS can be used to combine a few disks together under a common mount point. Otherwise, using the drives separately (setting up shared folders on each drive) works fine and the SNAPRAID parity drive will protect them all. (My personal preference, with a single SNAPRAID parity drive, would be no more than 3 data disks. That would be 4 total, with the SNAPRAID drive.)

      (Don't forget to set up an automated sync job. Schedule it for late hours, on a weekend, where using the server is unlikely.)

      2. No. There are several reasons why this wouldn't work.
    • thnks for your continued help....I have setup snapraid with 5 data/content disks (3tb ea.) and two parity (1 3tb and 1 4tb)...the data disks are separate at this point, and I am going to backup onto 8tb easystore usb drive using rsync usb bkup plugin...

      1. will the usb rsync backup create a tree reflecting drives/directories or simply shared folders with no reference to drives...
      2. UnionFs vs mergerfs....any preferences or reason for one over the other. Can these be installed after raid creation and sync, as I have configured at this point.
      3. will the rsync backup tree be any different if I do install UnionFs or mergerfs? Will it reflect directories and drives, or simply shared folders?
      thnks again
    • thank you gderf…
      1. Then, mergerfs would be implemented in OMV using the plugin...
      2. can this be installed onto an existing snapraid installation, or does this require starting over?
      3. Please explain "mergerfs mountpoints are excluded by SnapRaid"...(please see "beginner" under my generic avatar)
    • 1. Yes

      2. Yes. Snapraid protects individual disks. Combining drives with the plugin (openmediavault-unionfilesystems 4.X.X) will create a "merged" single mount point forthe contents of member drives. But the single drive mount points will still exist so SNAPRAID will be unaffected. (You won't have to start over.)

      3. Excluded in this context means not allowed.
      Why? The merged drive (I call it the Union drive) will be quite large. (In your case the Union will 15TB - consisting of 5x3TB.) Even if it was possible to protect the combined Union with SNAPRAID, remember the SNAPRAID rule - the parity drive must be as large or larger than the drive(s) being protected. Since 15TB drives are not common :) , you'd want to protect the members of the Union drive (as content drives) with SNAPRAID which would require at least 1each 3TB disk, or larger.