Disk removed, unable to re-attach it


I’m new here.
Just installed rockstor 3.9.1-16 on custom hardware. First the only hard disk attached was found and appeared in the GUI, I created a pool for it and I could copy files to it from my desktop.

For some reason I decided to remove the disk, I don’t know what I exaclty did but now the share is gone, the pool is gone and the disk is gone from the GUI.

If I do a rescan of the disks my attached disk does not come back up in the GUI.
is there something I’m doing wrong?

I’m migrating from NAS4Free to Rockstor, and have 8 disks with approx. 20TB of DATA I need to move.

looking forward to any suggestions, my CentOS knowledge is limited though.

@n0m0r3 Welcome to the Rockstor community.

Yes, if you remove a disk and it’s the only member of a pool then upon a web refresh or a reboot, when the system performs a fresh import, it will delete knowledge of that pool as there are no longer any members to represent it. But you should still have a disk named “detached-” which would retain the pool association. It may be that you also deleted this disk which would remove the last remnants of that pools references in the system. But re attaching the disk physically and using ‘Rescan’ on the disk page (or waiting a bit) and refreshing the disk page should result in the disk re-appearing, if it is known to the underlying system. And if the pool wasn’t deleted while the disk was attached the pool and all it’s shares, and snapshots should also re-appear. But if a disk containing a prior (undeleted) pool is re-attached with no ‘detached-’ disk references then you should still be able to import it. Unless of course you deleted to pool while it’s disk was attached and in which case any subvols will also have been deleted; after a warning indicating this has been shown of course (we need enhance this behaviour a tad I think: in time).

So the mystery appears to be why the disk is not showing up anymore. Could it be you are live unplugging / plugging hardware as this often requires specific bios settings for proper support. Also have you tried a power cycle / reboot with the problem disk attached?

It’s also worth noting that btrfs itself is still pretty touchy re-live unplugging / plugging drives when they are pool members so it’s best avoided for the time being. However the disk page info is below this layer so the disk should still show up. Essentially the disk page gets most of it’s initial info from the following command:


So I’d look to why the disk is not appearing in that command, if in fact it isn’t. If it does appear in that command and not on the disks page (after a refresh) then we have narrowed down the issue.

Hope that helps.

I can remeber I saw the ‘de-attached disk’, I also removed it manually, so this is nog a good idea I gues.

but after checking the cables, rebooting the complete hardware the disk does not re-appear. also the suggested command does not show the disk in question, only the boot/OS USB disk.

I’ll check again tonight to verify all cable connections, BIOS settings, if the disk is recognised by the BIOS and what happens after another reboot.

after a reboot, checking cables and connectors the disk, pool and share are back. thank you


You welcome and that’s good news, I’m guessing it was a dodgy connection. You might want to keep an eye on that.

Thanks for the update and hope things go more smoothly going forward.