RAID1 disk replacement (to increase capacity)

Insight & Feedback
1

I’m wondering if there’s been any way to expand the capacity of the drives we have in a RAID 1 array if I want to change them (for example, if I have 2TB HDDs and I add 4TB ones to make the RAID larger). That’s why I think SnapRAID would be better.

2

I believe RAID-1 disk replacement works, but ZimaOS cannot grow the array size through the UI.

If you replace 2TB drives with 4TB, the RAID will stay at 2TB until manually expanded by command line. I think advanced users could do this, but it isn’t supported in the interface.

SnapRAID is more flexible for mixed-size disks, but it isn’t real-time protection.

I suggest treating RAID-1 in ZimaOS as same-size replacement only until grow support arrives.

3

Yes, I know, that’s why I started this thread so you can see a problem that’s sure to happen, and that’s why I’m saying that Snapraid (another thread) would be great and if they could provide a solution.

4

Has anyone had success with growing the size of an existing RAID-1 volume? I just was successful in replacing 500GB drives with 1TB drives by removing one at a time, replace with larger disk and let the volume re-sync. So I now have the 1TB drives mirrored but my RAID-1 volume is still only 500GB. I cannot extend the file system because the underlining RAID-1 volume has not grown to 1TB. I have not been able to find the correct commands to do this. I am hoping someone has figured it out.

5

I did some more poking around and figured out the command-line tools to complete this task. I started with a 500GB RAID-1 volume with one 500GB file system mounted on it. I wanted to upgrade the disks to 1TB and grow the file system to use the additional space. Here are the steps I took:

  1. Power down ZimaOS and replace the first drive with a larger disk.
  2. Power up and use the “recovery” button in the GUI to start the rebuild on the new drive.
  3. Wait for recovery to complete.
  4. Power down the ZimaOS and replace the second drive with a larger disk.
  5. Power up and use the “recovery” button in the GUI to start the rebuild on the new drive.
  6. Wait for recovery to complete.
  7. Run the command in a ssh session, “sudo mdadm --grow /dev/md0 --size=max”
  8. The command “sudo mdadm --detail /dev/md0” will verify that the RAID volume has grown to the size of the new disks.
  9. RAID-1 volume will go into auto-recovery (rebuild) state again, wait for it to complete.
  10. Run the command “sudo btrfs filesystem resize max /your_file_system_name_here”
  11. Storage, System in the GUI interface, and running “df” in the shell will verify the file system is the size of the new disks.

FYI, I am running ZimaOS+ v1.5.4.

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