Best filesystem for MergerFS/SnapRAID

    • OMV 3.x
    • Best filesystem for MergerFS/SnapRAID

      I have 5x 8TB Red Drives that I want to use for mostly media storage and I intend to use MergerFS/SnapRAID.

      As the drives are empty, what would be the best filesystem for me to format them to for the long run?

      Ext4/BTRFS/XFS etc.

      Thanks for any guidance.
      OMV 4.1.4 Arrakis | 34TB SnapRAID+MergerFS
      Supermicro X10SLM+-F| Xeon E3-1285L | 16gb ECC Ram | LSI SAS9220-8i
      5 x 8TB WD Red | 2x 3TB WD Red | 128gb Samsung 830 EVO
    • I've just tried to format a disk to ext4 with OMV, it seems to go fine but produces this error at the end:

      Failed to get the 'ext4' filesystem implementation or '/dev/sda1' does not exist.

      I am unable to mount this drive.

      and upon reboot OMV does not launch and gives the following errors:

      [IMG:https://i.imgur.com/HPQdVJa.png]
      OMV 4.1.4 Arrakis | 34TB SnapRAID+MergerFS
      Supermicro X10SLM+-F| Xeon E3-1285L | 16gb ECC Ram | LSI SAS9220-8i
      5 x 8TB WD Red | 2x 3TB WD Red | 128gb Samsung 830 EVO
    • Jonatron wrote:

      I am unable to mount this drive.
      For the reasons clearly written in your screenshot as well as what 'the OS' is recommending to you. Your filesystem is corrupted, you need to run fsck manually and you need to use systemctl to get more information and to proceed. Though I'm a bit surprised that a filesystem corruption on a data drive is able to interrupt the boot process.
    • Since you asked yesterday which fs to choose, you report today a corrupted ext4 filesystem I would assume we're talking about
      • a new NAS build
      • a freshly created filesystem that shows already unrecoverable errors
      Filesystem corruption usually happens for a reason and if both assumptions above are right then first thing I would check is cable/connector problems. SATA sends data over the wire combined with a short CRC checksum so in case data corruption 'on the wire' happens the receiver can take notice and asks the sender for a retransmit.

      The SMART standard has an attribute defined to notify users of this problem: SMART attribute 199. Unfortunately some disks do not record these errors even if they happen and some disk families only too late (one of the reasons I would never ever buy any WD SATA drive again).

      TL;DR: Most probably data gets corrupted at the hardware layer. If your drives support it then checking for SMART attribute 199 is a great way to find out.

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

    • Okay well, I've managed to get a disk formatted correctly using the onboard SATA passed through to OMV from ProxMox.

      I was able to set up a share and transfer data to it from my desktop no problem.

      I then connected the single drive back to the HBA also passed through to OMV and whilst it shows up in OMV I am unable to access the share.

      This leads me to believe that the issue is either with my HBA or the breakout cables.

      I've ordered some new cables and will try those (I have tried other ends of the breakout cable with similar results already).

      Failing that I would conclude that it's either the HBA itself or the manner in which it is passed through, so will try some alternative BIOS/Firmwares.

      I've already been having trouble consistently making sure SMART is passed through, so perhaps I will skip running OMV in a hypervisor and consider my options.

      I checked the SMART entry 199 as you suggested and the value for my drive was 0.

      Thanks for your help, if you have any suggestions based on what I've said here it'd be appreciated and I will report back as my testing continues!
      OMV 4.1.4 Arrakis | 34TB SnapRAID+MergerFS
      Supermicro X10SLM+-F| Xeon E3-1285L | 16gb ECC Ram | LSI SAS9220-8i
      5 x 8TB WD Red | 2x 3TB WD Red | 128gb Samsung 830 EVO
    • Jonatron wrote:

      I checked the SMART entry 199 as you suggested and the value for my drive was 0.
      Did you read what I wrote above? 'Unfortunately some disks do not record these errors even if they happen and some disk families only too late'' (this being one of my reasons to avoid WD)?

      If you have WD disks you need to also check 'power on hours' and start/stop count. This behaviour to not properly deal with this SMART attribute is really annoying since usually cabling/contact problems occur with new disks.
    • tkaiser wrote:

      Jonatron wrote:

      I checked the SMART entry 199 as you suggested and the value for my drive was 0.
      Did you read what I wrote above? 'Unfortunately some disks do not record these errors even if they happen and some disk families only too late'' (this being one of my reasons to avoid WD)?
      If you have WD disks you need to also check 'power on hours' and start/stop count. This behaviour to not properly deal with this SMART attribute is really annoying since usually cabling/contact problems occur with new disks.
      I used the link you provided, and my drive has over 8 hours of power-on time (the drives have been connected for a while whilst I fiddled around with ProxMox) so the value give as zero rather than 253.

      Edit: my drives are WD so the above information was important to check.
      OMV 4.1.4 Arrakis | 34TB SnapRAID+MergerFS
      Supermicro X10SLM+-F| Xeon E3-1285L | 16gb ECC Ram | LSI SAS9220-8i
      5 x 8TB WD Red | 2x 3TB WD Red | 128gb Samsung 830 EVO
    • Well, the new breakout cables arrived and the drives still weren't playing nicely, so I reinstalled OMV as the main boot OS and everything now seems to be working fine, I can only assume in this case that the issue was between Proxmox, the HBA and the PCI passthrough settings.

      All my drives are now happily formatted to ext4 and I've combined them using MergerFS.

      My issue now is that I wanted to run a torrent client/nzb downloader etc in VMs/containers through VPN, will this be possible with OMV, would it be possible with Docker perhaps?


      Also, I have OMV installed onto a 250gb SSD, I also have a 60gb SSD from my previous NAS, would it be best to use the 60gb SSD for boot as OMV doesnt take up too much space, plus neither would any additional VM's I think.

      In that case:

      1) what would be the best way to copy my OMV installation and settings to the 60gb and use for boot

      2) could the 250gb SSD be of any use in this build for a cache drive or fast storage to download to before moving to the combined storage.

      Thanks again for your help with my previous issues, I am happy with the solution, even if it isn't what I originally intended, but there was probably always going to be on-going issues with it, in partiuclar the SMART pass through working intermittently at best.
      OMV 4.1.4 Arrakis | 34TB SnapRAID+MergerFS
      Supermicro X10SLM+-F| Xeon E3-1285L | 16gb ECC Ram | LSI SAS9220-8i
      5 x 8TB WD Red | 2x 3TB WD Red | 128gb Samsung 830 EVO
    • I think most people will tell you it's much easier just to manually screenshot or take some notes about your OMV settings, install OMV 4 fresh to the other SSD, and set it up from your notes.

      Personally, I installed a spare SSD I had lying around to use as Plex's transcode drive and the "incoming" file directory for my usenet downloader NZBGet. My torrent downloads go directly to my pool storage though.

      Also, Docker is a good solution for your requirements. I may be biased though, since I spent a lot of time learning it and wrote this guide for commonly used media server applications.