Nesting Raid 1 arrays in Raid Linear Mode

    • OMV 1.0
    • Nesting Raid 1 arrays in Raid Linear Mode

      Ok this might be a little complicated but maybe i can make it happen.

      So Raid10 as i understand it is simply a nested raid 0 + 1 or 1+0. Two drives mirrored and those two mirrors combined by raid0 or the other way around...

      So right now I have two raid1 arrays. One array of two 2tb drives and one with two 3tb drives. Now I could make a raid0 array with these by defining the two raid1 arrays as harddrives when creating a raid0 with mdadm. If I did this I would only have 4tb of space since it will use the smallest disk.

      To my knowledge Raid Linear Mode can take drives even of different sizes and line them up behind each other to built one big virtual drive.

      My question is: Is it possible to take these two existing raid1 arrays and use the Raid Linear Mode to create a big virtual drive of 5tb? And even better when needing more space can I just grow the array with for example another raid1 4tb to get 9tb?

      I am guessing it could be set up by something like this?

      Source Code

      1. mdadm --create /dev/md2 --level=linear --raid-devices=2 /dev/md0 /dev/md1


      Last question: Is there a way to loose no data when building this array? Lets say I have my data on the raid1 3tb and im adding the raid1 2tb behind it would everything be deleted?


      thanks guys for your help!


      edit: Ok i tried this in a virtual machine and creating the array is possible and works well. Now the best would be if someone could show me a way to keep the data.

      The post was edited 1 time, last by seife96 ().

    • You can always use the VM OMV appliance for testing. I've no idea if that is possible. However I'd just did a test. Here is SS of my OMV virtual machine.
      [IMG:http://i.imgur.com/DXn7sAi.png]

      Hope that it helps. You can download a preconfigured OMV appliance here
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      The post was edited 1 time, last by subzero79 ().

    • Haha great minds think alike! I just tried the same thing in my virtual machine! Any ideas if there is a way to keep the data or is it just smartest to backup my drive, then make fresh arrays and then at last put all data back on and link shared folders and then link that all back into the addons and fix permisions?
    • It is not possibly to do it with mdadm in the OMV web interface. What you want is snapraid (for big files, relatively static content) or greyhole (small files, dynamic content) and don't use mdadm at all.
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    • I guess it is possible. I HIGHLY recommend against doing it though. You thought people had problems when one array had to re-sync. Imagine if the two underlying arrays had to re-sync and then the top array had to! This is why raid 10 exists. I still would use snapraid or greyhole.
      omv 4.1.11 arrakis | 64 bit | 4.15 proxmox kernel | omvextrasorg 4.1.11
      omv-extras.org plugins source code and issue tracker - github

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