I had a rather unsetteling experience this evening.
I have been in a process of moving data to my Rockstor NAS, and am allmost finished with replacing / installing disks.
I had started a disk removal and let the system work on it. After some time I wanted to check up on the progress, only to find that the system was unresponsive. It didnt react to any input, and I couldn’t get into the command line. It seemed completely frozen. A bad thing to happen, I would guess, during a disk removal.
My only option was to cut power and reboot. The system came up, but Rockstor threw a lot off errors at me. Wouldnt let me see the pools and shares.
Messed around on the cmd line a little, but btrfs refused to mount the pool. btrfs scrub start /dev/sda only ran for 14 seconds scanning 2 GiB of data and showed no errors.
The cmd line also showed errors upon reboot about not being able to see the root tree on different drives.
Tried rebooting a few times, to no avail. Then decided to give up for now.
But reading about reparing btrfs I found something about a restore command.
I decided to try it, and booted the system. I entered the commands on the cmd line, but to my surprise the restore command told me the pool was allready mounted.
I went into the GUI, and (lo and behold) everything was accessible, and I can see the files on the shares, and open files etc. All drives show up as part of the pool, even the one in the process of being removed during the crash, just with less data shown on it (btrfs fi show).
I have started a scrub, which is slowly progressing, showing no errors until now.
Allthough everything seems fine, I am a bit startled by this.
I guess the best thing I could do was to let the scrub finish (looks like it could take about a day or so), see if errors was reported, and then continue where I left of?
Have anybody else experienced things like this? Especially a seemingly dead fs comming back to life like this on its own?