Losses:
* An HDD apparently failing at 0.5 MTBF.
* This weekend.
* All data between final backup & failure: more or less 2 hours, the most consequential of which was mail.
Gains:
* Bigger HDD.
* XP in installing anything in FreeBSD's USB images.
* XP in restoring ZFS snapshots.
* Learning my backup procedure needs slight tweaking, but fundamentally everything was right.
Net:
I have now experienced ZFS disaster preparation, disaster, & disaster recovery!
Please make backup copies of your PC, folks, if you aren't already. Don't forget to test your backups. Don't forget to write down your PC recovery & backup restoring procedure. And don't forget to save that procedure somewhere you can get to if all your data gets wiped out.