As I was recently trying to enable auto-switching audio to headphones, I borked my FreeBSD installation. Somehow the speakers stopped working, and the headphone output added a loud hiss. Unfortunately, I was unable to fix it.
My first thought was to reinstall the system, but then I remembered that I’ve read about ZFS Snapshots.
zfs list -t snapshot
revealed that FreeBSD has already created a few of those recently. I knew this OS and ZFS go hand in hand, but I was still pleasantly surprised.
To return the system to a previous version, all I had to do was
zfs snapshot <name>
and my system stopped responding. I was in X, so that’s entirely on one. But the rollback was so instantaneous that my first thought was that something fried.
After a good, old hard reset, everything worked as it was a few days ago. ZFS very well may be my new best friend.