Raid Options for my Setup

  • I'm currently in a transition period with my DIY NAS - Due to lack of budget at the moment, I would like to use what I have available in the most sane and common sense way possible.


    I originally was a FreeNas/TrueNas user. Lost a drive in my array. Don't have the $ right now to save my pool. Backed up all my data and currently running a trial of unraid. currently on trail waiting on the parity to rebuild (now on to OMV)


    I have OMV running in a VM (Proxmox host) and it currently is housing my backup data, but non raid as this is only temporary.


    I have four 4TB drives and four 3TB drives in my system that are still good. These were originally a raidz2 striped vdev. however I am curious about the raid6 options available with OMV.


    Would it be best to run two separate raid5 setups, one large raid 6 pool and upgrade my remaining disks, or something entirely different?


    What are your thoughts. Please tell me I should abandon unraid and seek this alternative. :) I have 14 days to decide.

  • You could have two raid 6 pools using mdadm - one of 4TB drives and one of 3TB drives - but raid 10 would be better (no parity rebuilds).


    If you had one large raid mdadm pool, you would lose 1 TB on each of the 4TB drives since mdadm uses the space of the smallest drive on each drive.


    Unless you have 10gig networking, I would look at building a unionfilesystem pool (uses mergerfs) and use snapraid for parity.

    omv 5.6.9 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.5
    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 started some research. apparently i need to install the omv-extras.org plugin to take advantage of unionfilesystem (also never heard of that option) until now.


    but I have some options to consider while I test unraid. So I greatly appreciate your quick and helpful response. I'll also look at raid10

  • So got those installed on my VM. i am hesitant to test as that is currently housing my backup data.. but I am tempted to stop my unraid operations and look at my options... essentially this is what unraid is at it's core with the plugins you suggested.. I appreciate this eye opening experience. Doing some math, I considering running raid6 though as I am more familiar with that. I can put forth efforts to upgrade my remaining 3tb drives down the road.


    I'm comfortable with the space penalty. What I want is something ultra stable without going back to freenas/truenas (if at all possible).


    that being said, how stable are setups with mergerfs and snapraid vs native raid6 built into omv?

  • mergerfs is going to more stable than any other option including freenas because the drives are individual filesystems (ext4 is fine) meaning no assembling to ever go wrong. mergerfs just pools them together for reads and write but you never lose the ability to use the underlying drives just like normal.


    Even without snapraid, mergerfs would allow you to only lose the the files on the drives that failed. snapraid is just a scheduled task (not realtime but most users don't need realtime parity) and creates a parity file on a disk. So, there is no stability questions there either. If the parity run fails, you don't lose any info. And since any kind of raid or snapraid isn't backup, these are all questions about availability.


    I do use mergerfs and love it. I don't use snapraid because I backup to a second (and third) server with borgbackup which does my bitrot detection along with dedupe and compression.

    omv 5.6.9 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.5
    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!

  • what are your thoughts on xfs vs ext4?

    I prefer ext4 only because the recovery tools are better. One of my backup servers is using xfs so that if there was a major ext4 issue, it wouldn't hit all of my files.

    omv 5.6.9 usul | 64 bit | 5.11 proxmox kernel | omvextrasorg 5.6.2 | kvm plugin 5.1.5
    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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