What to do if your ZFS pool vanishes!

[allanl9]

I shut down my FreeNAS-11.3-U5 system for two weeks and on restarting, the single pool vanished! No matter what I did, it wasn't there under Storage|Pools although the drives were and healthy. I even restored the system backup thinking that it may work. It didn't.

After a number of tries to bring the pool back, I shut the system down and unplugged the USB drives used to boot the system. I downloaded the SAME FreeNAS version that was running without the pool, burned it to a DVD and reinstalled onto another USB stick plugged into the NAS.

When I brought the system to life, the new software saw the original pool and it was restored in a few seconds. I then restored the original config file backup and all was back to normal.

This worked, but is there another way?

 

[JaimieV]

This shouldn't happen.
If you bring it up on an old boot stick, does it still not see the pool? If so, there may be some investigative troubleshooting to be done.

 

[allanl9]

I know, but it happened and I had to fix the problem. I've already deleted the original USB drives as I wanted to reuse them as mirrored USB drives, they way they were. I should note that using ftp, the pool was not visible in the /mnt folder. When rebuilt, there it was.

Life isn't perfect, but I wanted to help others that have this unusual problem.

 

[JaimieV]

There would have been at least one thing to check from the GUI (Storage, Pools, Add, Import existing pool - may have seen it) and various things on the command line to check for the presence and state of the missing pool. Without the problem bootup or at least the logs there's really nothing to look into I'm afraid.

 

[allanl9]

I did check this. It found NOTHING to import! I think that it just lost the pool as ftp to /mnt didn't find anything! I had mirrored USB drives and neither worked. The purpose of my forum message to let people know that this MAY be a solution to a disaster if something similar happens. Try everything else, and then get your USB flash drive out.

 

[JaimieV]

Nod nod. It doesn't make any sense that it worked, but it's worth a try!