[HowTo] SnapRAID in OMV

  • Do i understand correctly that normall you can not make an file system larger then the largest disk size, but when i make i "enable pool" in the plugin it is seen as 1 file system? I have and directory larger then my biggest disk and would like to keep it that way.

  • Your Parity drive has to be at least the same size as your biggest filesystem. Without testing, I guess you can use RAID0,1,5 filesystems for Snapraid too

  • Hey Guys,


    I've just installed SnapRAID and it's running well. (3 Disks with 1 Parity, Content on every Disk)


    Now I want to setup a Cron-Job to sync automatically the Data but I'm a little bit confused.
    I've read this Thread almost 3-times but I don't get it exactly.


    What is the need for "Scrub"?


    I just wanna:
    - Sync every x days
    - Scrub? (Is there a need for a script? Isn't it running almost autmatically every 7days by default? (Diff Script settings in Plugin-Settings)
    - Diff? (Why should I need a list of the changed files?)
    - maybe a Status / Notification


    Is the script "omv-snapraid-diff" located in /usr/local/bin all I need therefore?
    Is there any need to customize this script or will it run "out of the box"?


    At least another question:
    I have 2 Data-Disks, one with 2TB, one of 3TB. Parity-Drive has 4TB.
    If I wanna swap the 2TB disk for an 4TB disk, will I handle it the same way as the 2TB disk is defective?


    Thank you very much!

  • Now
    I want to setup a Cron-Job to sync automatically the Data but I'm a
    little bit confused.


    Just change the GUI settings like you want and setup a daily cron job with the command /usr/local/bin/omv-snapraid-diff


    I
    just wanna:
    - Sync every x days
    - Scrub? (Is there a need for a
    script? Isn't it running almost autmatically every 7days by default?
    (Diff Script settings in Plugin-Settings)


    Sync every day -> daily cron job (see above)
    Scrub -> it depends on you
    See the SnapRAID manual #4.2
    Scrub
    runs with the above script if configured (default all 7th script-run).
    If you set it up daily, then it runs one tome every week.

    -
    Diff? (Why should I need a list of the changed files?)


    Just to make sure, what files have changed :) before running sync


    -
    maybe a Status / Notification


    Notification per mail? It is already there. Please explain more detailed.

  • Okay, I think I have to start new with SnapRAID.


    To have a look how it works I copied some new files on my Datadisk, startet manually "Diff" and then a "Sync".
    Sync always stucked, even kill-command can't stop the process. I've let it run the whole night but nothing happend.


    It seems that the Filesystem of the Parity-Disk is broken, at least OMV is telling me during startup.
    The Parity-Disk is a new 4TB WD Disk which was formatted as ext4 as I setup SnapRAID.
    So I'm sure the disk is not defective.


    I'll have to take a look for the cause of this.


    Now I wanna setup SnapRAID completely new and have a question about pooling.
    The SnapRAID Manual says: The Paritydisk has to be at least the same size as the biggest Datadisk, or bigger.
    I read in this Thread: The Paritydisk has to be at least the same size as the biggest Filesystem, or bigger.


    Whats right? If I do pooling, the biggest Filesystem would be 7TB (4TB+3TB) so the Paritydisk can't be same size or bigger.
    The biggest Datadisk would be 4TB, so a 4TB Paritydisk would fit.


    I wanna pool with Unionfilesystem, using "aufs".


    What do you think? Whats right?


    Thanks.

  • Only the size if the datadisk matters, not the size of the filesystem. Your 4TB-HDD for the Parity-disk is enough for Data-HDDs up to 4TB each.


    But please make sure that you fill your data-disks only about 85-90% if the parity-disk is the same size as your data-disks. Above this value the parity-file may not fit onto the parity-disk. If your data-disks are 2TB and your parity-disk is 4TB, you don't have to worry about ;)


    With pooling, your datadisks show up as one mount in OMV, which you can use for SMB,NFS or $whatever. I'm using AUFS for pooling, too.

  • Thanks a lot for your help.


    One Datadisk is nearly full (80-85%, the 3TB one) so maybe that caused the Filesystem-Error on my Paritydisk? (Paritydisk was ca. 50% filled only)??
    No idea and I don't think so, but because the 3TB disk was nearly full I decided to pool with the 4TB disk to have enough space in future.


    I will buy another 4TB disk for parity and will give it another try. I'm sure I will come back to this Thread when the disk is here :)


    Thanks!

  • Hi Guys,


    Been a long time user of Freenas, Shifting to OMV - Snapraid this week, so doing my homework on the same.


    Wanted to know the following :-
    1. Any reason why snap raid is not updated to the latest in omv extra's plugin? its still in 6.3. Is it ok if i use the compiled version of snap raid ? Would i be allowed to apply updated further down the line from the plugin?
    2. Is there any documentation on what snapraid sync and fix do? Because there are contradicting information on what to do if the parity disk fails..
    3. Is there any way i can mount a ZFS pool in omv, i understand that freenas 9.3 is too new for the plugin to work, wanted to transfer my data from the 3X 1TB disk to 2x 4TB disks.
    4. I see that after changing a disk incase of failure and doing a sync again gives me an error.. I have to try sync and fix through terminal for it to work.


    Hopefully i didnt ask any dumb questions, if so please forgive me; am new to the system :)

  • 1. Didn't notice there was a newer version. You should be able to use a compiled version.


    2. http://snapraid.sourceforge.net/manual.html


    3. Unfortunately, zfs-on-linux doesnt support zfs from freenas 9.3.

    omv 5.6.13 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.6
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

  • Thanks for the fast response.


    Great, so i can use the compiled version and then upgrade the snap raid plugin when available right?. I am favouring the new version as it is also reporting smart Data. I found that once the parity is made through new version of snap raid its not possible to go back without removing parity, which is a risk. Is there any ppa available for snap raid as well?


    Regarding the 4th point, that after changing the disk, sync and fix don't work from gui, am i doing something wrong ? it asks me to first do snap raid fix -e, is there anyway to automate this?


    And do you think its possible to remove the disks added through Snapraid ui to re-appear when adding another disk? (Sorry if am confusing you )


    By the way, Great Job on the Snapraid Plugin team..

  • I actually don't use snapraid. So, maybe solo can answer your questions. I will upgrade plugin in a bit.

    omv 5.6.13 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.6
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

  • Oh Thanks a lot.


    To be frank am really scared of shifting all my content to EXT4 + Snapraid + OVM.. :) I have been experimenting with it since few days on VM to try and get accustomed to it before the shift.


    I wanted to go from Mirror to Raid 6 to Raid 5 as i keep buying more hardisks, and it seems Snapraid is the only one which allows me to do so.

  • You shouldn't be afraid to try it. snapraid runs on top of the filesystem and doesn't alter your files. You can remove it at any time. I think it is safer than mdadm. None of them are backup though - just redundancy.

    omv 5.6.13 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.6
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

  • I didn't update the plugin itself. So, that is just a label. It doesn't read the version from anywhere. I will fix it.

    omv 5.6.13 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.6
    omv-extras.org plugins source code and issue tracker - github


    Please read this before posting a question.
    Please don't PM for support... Too many PMs!

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