RAID5 has disappeared after reboot

  • Hi all,
    after reboot I don't see anymore RAID5 composed by 3 disks.
    This is my report:




    Thanks in advance to everyone wants help me.

  • This is on a Rasp Pi, using USB for raid purposes was disabled in OMV4.


    Can anyone help, highly unlikely;
    1) mdstat only references one drive
    2) blkid is missing relevant information
    3) mdadm.conf contains no raid information
    4) the last output which I assume is --detail --scan lists one device
    5) fdisk does appear to list all three drives


    There is no information on the type of drive or how they are connected i.e own power supply etc, nor what Pi version.


    If there was any data on that raid chances are it's gone, you could search for references regarding mdadm (software raid) and start from there.

  • Can you tell me other suggestions?

    Not really, you could start with mdadm --detail /dev/sda do that with all three drives and see what information is returned, but as to re assembling it, highly unlikely.
    My guess is you completed this from the command line, hence the empty mdadm.conf as this step was not done.

  • When i send this command:

    Code
    #mdadm --examine /dev/sdc1

    I obtain this:


    So I guess the RAID5 still exist. Any suggests?

  • --examine /dev/md127
    nothing appear


    mdadm --examine on /dev/sda
    No md superblock detected on /dev/sda


    The same for /sdb


    At this point I would try to send this command found in other post in similar case:
    mdadm --create /dev/md127 --level=5 --assume-clean --verbose --raid-devices=3 /dev/sd[abc]
    Do you agree?

  • the steps to config a raid are:


    #apt-get install mdadm parted
    #parted /dev/sdX mklabel gpt
    or
    #parted /dev/sdX mklabel msdos
    depends on bios and uefi
    #parted /dev/sdX set 1 raid on
    do it on all raid disks XYZ
    next single step is optional and depends if you want raid disks (jump) or raid patitions (do it).
    #parted -a optimal -- /dev/sdX mkpart primary 0% 99%
    on partition raids do a
    #mdadm --create /dev/md0 --auto md --level=5 --raid-devices=3 /dev/sdX1 /dev/sdY1 /dev/sdZ1
    on disk raids do a
    #mdadm --create /dev/md0 --auto md --level=5 --raid-devices=3 /dev/sdX /dev/sdY /dev/sdZ
    this will take a looooong time.
    watch about it at
    #watch cat /proc/mdstat
    if its ready and up, take a look at
    #cat /etc/mdadm/mdadm.conf
    it shoud contain a line like
    ARRAY /dev/md/md0 metadata=1.2 name=nas:md0 UUID=264....bla blub
    if not, do a
    #mdadm --detail --scan >> /etc/mdadm/mdadm.conf
    now your raid appear and is hopefully fine, view it with
    #mdadm --detail /dev/md/md_test
    if you break the (re)assmebly... what i think, you need to reassemble.
    ##mdadm --assemble /dev/md0 /dev/sdX(1) /dev/sdY(1) /dev/sdZ(1) --force
    (depends on Disk or Partition arrays) and think about.. it needs lot of time!
    if the array was ready and gone, try
    #mdadm --assemble --run --force --update=resync /dev/md0 /dev/sdX(1) /dev/sdY(1) /dev/sdZ(1)
    if the array is fine, you can set up a FS.
    maybe this one.
    #mkfs.ext4 -b 4096 -E stride=128,stripe-width=384 /dev/md0
    and mount it via omv or by hand in /etc/fstab
    if you wanna boot from, install grub and, make a
    #update-initramfs -u
    sometimes raids appear as md0 or md127, i dont know why.
    and last but not least...read a good mdadm howto!

    Equipment: a few Computers, lot's of waste heat, little time and a Pile of work.


    When solving problems, dig at the root instead of hacking at the leaves.

    Edited 5 times, last by Rd65: some corrections ().

  • depends on bios and uefi
    do it on all raid disks XYZ

    Did you actually read any of this thread! The OP is using a Raspberry Pi 3B+ the option for creating a raid using USB devices was disabled on OMV4. Does the Pi have a bios no! Does it have uefi no!


    Do you agree?

    I don't agree with doing anything like this on a Raspberry Pi least of all a Pi 3B+ and as I have said to others who have attempted this, don't call us, we'll call you :D it is simply a bad idea. Also, as far as I can remember the USB ports share the same chipset as the Ethernet.

  • Did you actually read any of this thread! The OP is using a Raspberry Pi 3B+ the option for creating a raid using USB devices was disabled on OMV4. Does the Pi have a bios no! Does it have uefi no!

    yes i read and decide to write a system independend minihowto about setup/rescue a raid.
    as the title describe:


    the steps to config a raid are:


    but no.. on pi there is no uefi.... so i must be wrong...


    thank you geaves

    Equipment: a few Computers, lot's of waste heat, little time and a Pile of work.


    When solving problems, dig at the root instead of hacking at the leaves.

  • the steps to config a raid are:

    :) I did read that, but setting up a Raid on OMV can be, and is recommended to be completed within the GUI (makes it easier for home users)
    But the Pi is a PITA when it comes to this due to issues regarding under powering, that's why a Raid setup using USB drives was removed from OMV. Yes, as you have shown in your minihowto it can be achieved/done from the command line, but on the Pi or any SBC using USB for this is not really a good idea. :)

  • i agree, that it is not a good idea to raid via usb. absolutly!
    but its not impossible, for learning and testing scenarios... why not?
    In my view the pi is invented as a educational computer!
    so what is the problem testing raid5 with 3 usbsticks??
    you may use it for other challeges...like pi-hole, a bt-seeder, tv/media/plex head or whatever.. but as a pi user you are always at your own. Most people.. even the guys with a pi.. are able to use a shell too.


    But about omv and Raid as (Linux) principe, you are simply wrong.
    The tool to admin softraids is not omv, it is mdadm.
    show me in omv how to insert a spare drive to a raid.. or manage a rebuild, stripe sizes, and so on...
    its nice to see how easy it is to klick a simple raid together in omv ... but thats not all. And i think you know that too.


    So why do you dont tell the poeople where to find knowledge about raids, even if you cant or will not help?
    Is omv your only way to get access to a system? Why you try to hide things on a open system and tell people to use omv instead learning using the right shell commands? You try to protect people from the system but you make the people dependent!
    I would understand it if you work on a better version of omv-raid ... but ...

    Equipment: a few Computers, lot's of waste heat, little time and a Pile of work.


    When solving problems, dig at the root instead of hacking at the leaves.

  • Why you try to hide things on a open system and tell people to use omv instead learning using the right shell commands?

    If you have been around here as long as geaves has been, you would know that many people do not want to learn shell commands. No one is hiding anything. If they want to know how to work with raid on an OMV box, just google for debian/ubuntu tutorials. But you will find that they want to use the web interface. If something is missing, I guess it is strange it isn't in more demand.

    So why do you dont tell the poeople where to find knowledge about raids, even if you cant or will not help?

    Why do you treat people so poorly who are just trying to help? If he can't help, how would he tell people where to find knowledge? Pretty sure everyone knows about google. Most people find this forum very helpful. You seem to think it and OMV itself are terrible. Not sure why you use it if everything is done wrong. I've been a Linux admin for over 20 years and I find OMV very time saving. Is everything perfect? no but it does a damn good job for the targeted user.

    Most people.. even the guys with a pi.. are able to use a shell too.

    Definitely not on this forum. Most pi users are Windows users who have never used the command line.


    so what is the problem testing raid5 with 3 usbsticks??

    You will have to create it from the command line. The web interface purposely blocks users from create raid arrays with usb devices. If you want to learn about raid, you should start with the command line anyway. But testing on the RPi is still a terrible idea (maybe not as bad with usb sticks) because the usb ports don't always activate early enough and/or the usb drives aren't spun up at boot assembly time.


    show me in omv how to insert a spare drive to a raid.. or manage a rebuild, stripe sizes, and so on...

    The grow command can add a spare. Ideally you shouldn't have to manage a rebuild and it is probably had to do that from the web interface since the system will boot to single user. Very few users need to manage stripe sizes. Some decisions to not show settings are made to keep the web interface simple.

    omv 5.3.9 usul | 64 bit | 5.3 proxmox kernel | omvextrasorg 5.2.6
    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!

  • Maybe I value the abilities of the audience wrong, yes.
    but this is more a philosohic point because you can not treat everyone the way you do the stupidest.
    I know what I'm writing about, I'm a supporter to, but in a different environment and i know the phrases that needed to survive.
    but this is offtopic.

    Equipment: a few Computers, lot's of waste heat, little time and a Pile of work.


    When solving problems, dig at the root instead of hacking at the leaves.

  • you can not treat everyone the way you do the stupidest.

    Wrong. I don't treat anyone like they are stupid. I try to match my support to their skill level. If they ask for more advanced help, I give it to them.

    omv 5.3.9 usul | 64 bit | 5.3 proxmox kernel | omvextrasorg 5.2.6
    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!

  • thats my view of things too and i agree with your statement. in general and related to your support.
    But the thread starts with geavis... my criticism was for him.

    Equipment: a few Computers, lot's of waste heat, little time and a Pile of work.


    When solving problems, dig at the root instead of hacking at the leaves.

  • Wrong. I don't treat anyone like they are stupid. I try to match my support to their skill level. If they ask for more advanced help, I give it to them.

    This is difficult to do on a regular basis, while taking into account the unknown philosophies of all comers and near endless possibilities.


    Is everything perfect? no but it does a damn good job for the targeted user.

    That's just sacrilege. :D

    But the thread starts with geavis... my criticism was for him.

    I get on @geaves myself, from time to time, for being such a nice guy.

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