Hey fellow Selfhosters! I need some help, I think, and searching isn’t yielding what I’m hoping for.

I recently built a new NAS for my network with 4x 18TB drives in a ZFS raidz1 pool. I previously have been using an external USB 12TB harddrive attached to a different machine.

I’ve been attempting to use rsync to get the 12TB drive copied over to the new pool and things go great for the first 30-45 minutes. At that point, the current copy speed diminishes and 4 current files in progress sit at 100% done. Eventually, I’ve had to reboot the machine, because the zpool doesn’t appear accessible any longer. After reboot, the pool appears fine, no faults, and I can resume rsync for a while.

While the workaround seems to be partially successful, the point of using rsync is to make it fairly hands-free and it’s been a week long process to copy the 3TB that I have now. I don’t think my zpool should be disappearing like that! Makes me nervous about the long-term viability. I don’t think I’m ready to drop down on Unraid.

rsync is being initiated from the NAS to copy from the old server, am I better off “pushing” than “pulling”? I can’t imagine it’d make much difference.

Could my drives be bad? How could I tell? They’re attached to a 10 port SATA card, could that be defective? How would I tell?

Thanks for any help! I’ve dabbled in linux for a long time, but I’m far from proficient, so I don’t really know the intricacies of dmesg et al.