FreeNAS 11.3U5 - all zpools are offline after power cycle(s)

[djidji perroto]

I'm running a FreeNAS system for ~ 10 years, doing backups/upgrades when components ask to be replaced.
Current setup is (was?) a 4 SATA drive box, one mirrored pool of 2 drives for necessary stuff, one striped pool of 2 drives for less important stuff. Boot from USB stick. All this for home backups/smb sharing.
Last known successful scrubbing of the pools was Jan 17.
Two days ago I noticed my system was not responding. As I have normally have no console I pressed the restart button (maybe couple of times).
I then hooked it to a monitor and saw the boot was failing (like in no boot volume found - "This is a freenas data disk, insert boot media...").
I assumed a failed usb stick and went to the store to get a new one (has happened at least once in the past).
A couple of tries later I was actually able to boot from the original usb media - with lots of errors on the console.
And when finally the GUI went up it shoes both zpools offline. Disks are visible from the Storage menu.
Any idea how to proceed?
I'd like to rescue at least part of my data...

 

[sretalla]

Take a config backup from System | General and install a fresh copy onto the new USB, then restore the config.

Ideally that will be enough to bring your pools back.

If not, go to Storage | pools and import your pools from there.

If you aren't successful after all that, we can discuss some command line stuff to see what can be done.

Don't worry, it looks like your pools will be fine, all your data is likely to be safe.

 

[djidji perroto]

Thanks @sretalla did as instructed.
After installation the system boots normally but shows no pools.
Restored the config.
Now stuck on boot with a series of messages
efipart_readwrite: rw=1, blk=xxxx size=yyy status=7
and
ZFS: i/o error - all block copies unavailable
...
Failed to find bootable partition
Failed to start image provided by ZFS (14)onds

I'm assuming the zfs boot partition on the new USB flash drive got corrupted upon config upload (too much coincidence?).
Shall I start from scratch and restore to a backup config from last Oct?

Update: I did an upgrade on the newly-installed-then-damaged USB stick, preserving the db. After the restart the situation is back to normal - all pools are back online, no visible errors.
What should I do to make sure I'm safe?