Moving the NAS Off My Desktop (And What ZFS Doesn't Tell You)

An old gaming PC gets a second job

I had an i7-4790K sitting around on an MSI Z97 board, and instead of letting it collect dust I gave it 32GB of DDR3, a spare GTX 1050, and a job: become the always-on box that holds the family's files. The plan was to pull the two IronWolf drives out of my desktop and let this box be the authoritative NAS instead.

Exporting the pool the right way

ZFS makes this easier than I expected, as long as you do the boring step first. You export the pool with zpool export ironwolf-mirror before you touch a single cable. Skip that and the new machine can fight with leftover metadata from the old one. I connected the drives to the Intel chipset SATA ports on the Z97 board rather than the ASMedia ones, since I'd read those can be flaky, and then ran zpool import on the new box. The pool came back clean on the first try, which honestly surprised me.

The part that actually bit me

Here's the thing nobody tells you: ZFS doesn't care about usernames, it cares about UIDs. My desktop had a user called chance at one UID, and when I created the same username on the new box, Linux handed it a different UID by default. Every file on the pool still belonged to the old number, so from the new machine's point of view, none of it was mine. I had to go back and recreate the accounts with matching UIDs to fix it. Lesson learned the annoying way.

Samba doesn't travel with the pool either

Once ownership was sorted, I still couldn't log into the shares from any of the family's devices. Samba passwords live in a separate database, passdb.tdb, that has nothing to do with ZFS and doesn't move with it. Every user needed smbpasswd -a run again on the new box before their login worked. Not hard, just one more thing that isn't obvious until it bites you.