Unable to create a RAID 1 array

  • Hello,


    I am new to OMV and have run into a snag setting up a RAID 1 array. I am able to see both disk in the Disk manager and I can wipe them. When it comes time to create the RAID 1 array it allows me to select both disk and choose the RAID level. Shorty after starting I get the following message:


    Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C; omv-mkraid /dev/md0 -l mirror -n 2 -N Data /dev/sdc /dev/sdb 2>&1' with exit code '1': mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 mdadm: size set to 488255488K mdadm: automatically enabling write-intent bitmap on large array mdadm: creation continuing despite oddities due to --run mdadm: unexpected failure opening /dev/md0


    Error #0:
    OMV\ExecException: Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C; omv-mkraid /dev/md0 -l mirror -n 2 -N Data /dev/sdc /dev/sdb 2>&1' with exit code '1': mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device. If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
    mdadm: size set to 488255488K
    mdadm: automatically enabling write-intent bitmap on large array
    mdadm: creation continuing despite oddities due to --run
    mdadm: unexpected failure opening /dev/md0 in /usr/share/php/openmediavault/system/process.inc:175
    Stack trace:
    #0 /usr/share/openmediavault/engined/rpc/raidmgmt.inc(260): OMV\System\Process->execute()
    #1 [internal function]: OMVRpcServiceRaidMgmt->create(Array, Array)
    #2 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
    #3 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('create', Array, Array)
    #4 /usr/sbin/omv-engined(536): OMV\Rpc\Rpc::call('RaidMgmt', 'create', Array, Array, 1)
    #5 {main}


    Any help would be greatly appreciated. I know I am missing something small, but what I dont know? I do have another drive (not part of the array) mounted that I running plex on.


    Thank you,

  • I was trying to build a RAID 1 with two blank disks, neither one has omv installed.


    I am using a raspberry pi for this and omv is installed on the SD card. I also have another hard drive that media for my plex server.

  • I am using a raspberry pi


    Three important rules:


    • Don't do RAID with USB disks
    • Don't do RAID with unreliable hardware since it will fail anyway
    • Don't use USB disks behind an USB hub

    So please stop now since what you're trying to do is a recipe for failure (Raspberries are nice toys for some stuff but from a NAS point of view simply unreliable crap. Everything is behind an internal USB hub and these things are prone to underpowering problems)


  • The configuration that I am using is:


    • Raspberry Pi 3 with a 32Gb SD - OMV installed on this.

      • -standard power supply for the Pi
    • 1 WD USB3 1Tb passport that has Plex media
    • 1 USB3 external hard drive docking station with 2 650Gb toshiba drives.
    • Connected via ethernet to my home network.


    Three important rules:


    • Don't do RAID with USB disks
    • Don't do RAID with unreliable hardware since it will fail anyway
    • Don't use USB disks behind an USB hub

    So please stop now since what you're trying to do is a recipe for failure (Raspberries are nice toys for some stuff but from a NAS point of view simply unreliable crap. Everything is behind an internal USB hub and these things are prone to underpowering problems)

    While this is true, not everyone has the money to buy new equipment. I am trying to use what I have and make it work the best that it can. My reason for trying to RAID would be for fault tolerance. Sure I could mount both drives and copy the data between the two on a schedule. I would like to have something more automated.


    Before this I was using R-sych and it was not the best. I came across OMV and thought that it would make things better. Plex is up and running like a champ. Now I just need to come up with a good solution for the hard drives.

  • Now I just need to come up with a good solution for the hard drives

    Impossible on a Raspberry Pi. Also RAID-1 is close to stupid in a home installation (why do you need availability? Do you run a business on your SBC?). RAID is not backup! If you care about your data you use something that ensures data integrity and implements versioning since primitive sync mechanisms like RAID-1 deliver zero data protection. Everything that is lost/corrupted on one drive is the same on the other.

  • Ok, so the Pi should have enough juice to not under voltage.


    Could you test your USB dock on another pc and test if it is possible to create a Raid1 there?
    Maybe you're running in a hardware issue with the dock.


    A Plan "B" could be to generate a LVM with both of the disks.



    Nevertheless keep in mind that a single system with a Raid 1 is no backup for your data.
    If you plan to use this setup as a productive system @ home you should think about a separate hard drive to copy your data to.

  • Nevertheless keep in mind that a single system with a Raid 1 is no backup for your data

    RAID with something crappy as a Raspberry Pi is horribly stupid. You need a well tested backup to implement this weird way to loose your data. And if you have a good backup solution at home you usually don't need availability anyway (and that's all RAID-1 tries to provide. With utterly unreliable hardware like any RPi impossible of course)

  • Thank you for your advice. I really appreciate you taking the time to work with me instead of just telling me I am stupid. I do have a separate disk that I occasionally (sometimes or when i remember) attach for backup purposes. I place it in my fireproof safe to protect it. This effort is being made to learn a few things, make the best use of what I have available, build in a little fault tolerance in and come up with a good solution for me.


    The drives work fine on the windows side, but I don't leave any of my computers running day and night. The Pi is probably the only device in my house I leave powered up. We are "thrifty" and do not have the money to throw away. This is also why I cannot simply go out and buy a whole new box and do all kinds of fancy things like someone else mentioned. I am firm believer in making do with what I have and trying to use it to its full potential.


    So far I like OMV and have it running my plex media server. I think once I figure out the data share side of the equation I will be all good.

  • So you have a backup hdd in a fireproof save, that's good.



    The drives work fine on the windows side, but I don't leave any of my computers running day and night.

    This meas you already created a raid 1 on windows and checkt the function.
    Don't get me wrong. You already wrote that the pi is able to see both HDDs and when it comes to the Raid it failed.
    So if you just plugged in the HDD Dock on Windows and checked if the HDDs are visible you did only half the test and need to check if the Raid is created successful.

  • build in a little fault tolerance in

    That's impossible with shitty hardware like a Raspberry Pi (reasons above). If you have 2 HDDs you want to use for 'fault tolerance' then why not learning how to stop following stupid advices (the useless mdraid-1 route so many sites on the net recommend for exactly no other reason than having no clue) and use them in a proper way to provide a bit more protection?


    Anyway: No further advice from me. It's your failing setup (and data loss) not mine :)

  • I just have the need to volunteer this observation.


    I have read thru this whole post in hopes of learning, being that I was attempting something very similar, but could barely stomach reading it to the very end.


    First of all whomever is allowing tkaiser to be a moderator really needs to scrutinize social skills and level of arrogance. Instead of demeaning someone for what they are trying to accomplish and voicing narrow minded point of view he may try and be polite and helpful. If he cannot moderate with a sense of dignity then maybe he should just get the hell out, and go somewhere else.


    Honestly I have read a lot of post and technical threads over the years being an IT Administrator and evolving later in life into a senior software engineer. There is always a character that has to antagonize someone else, but I can't say I have ever seen someone that is supposed to be a moderator act like this.


    Just for the record tkaiser wins the award for the biggest douche ever. Probably doesn't matter, judging by his face he appears dumb enough to take pride in it.


    J Out....

  • I just have the need to volunteer this observation.


    I have read thru this whole post in hopes of learning, being that I was attempting something very similar, but could barely stomach reading it to the very end.


    First of all whomever is allowing tkaiser to be a moderator really needs to scrutinize social skills and level of arrogance. Instead of demeaning someone for what they are trying to accomplish and voicing narrow minded point of view he may try and be polite and helpful. If he cannot moderate with a sense of dignity then maybe he should just get the hell out, and go somewhere else.


    Honestly I have read a lot of post and technical threads over the years being an IT Administrator and evolving later in life into a senior software engineer. There is always a character that has to antagonize someone else, but I can't say I have ever seen someone that is supposed to be a moderator act like this.


    Just for the record tkaiser wins the award for the biggest douche ever. Probably doesn't matter, judging by his face he appears dumb enough to take pride in it.


    J Out....

  • I had the same exact thoughts - douche was the exact word that came to me as well. I registered for this forum just to give you a "like" for your observation!

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