My backup server died in June 2021:
- Acer laptop with 800mhz AMD cpu 2010, machine storing the backups for the other machines
I had debian bullseye with ZFS installed on it.
The CPU fan broke and ZFS killed the machine because I was tranfering terabytes of data and ZFS uses a lot CPU resources on this machinei and the CPU became too hot.
The computer became unbootable because the ZFS root partition on the internal disk was not found anymore.
To recover the data on the internal disk, I tried debian live which didn't work because the computer was turning itself off when compiling the ZFS kernel module.
So I decided to copy FreeBSD on a USB key and use the live environment. ZFS is the default file system in FreeBSD, there is no need to compile the ZFS kernel module.
The pool on the internal disk was not exported, so I used
zfs import before mounting the datasets:
Then I used
scp to copy the data to another computer.
I had also a 1.5tb external disk with ZFS, the pool in this drive is unreadable:
I restored the data from backup.