Some of the ikiwiki configuration files on dragonflybsd.org were accidentally overwritten during a software upgrade. Normally this would mean some work to locate and replace them from backups, but since it was a Hammer volume, a quick look in /var/hammer/usr/… found them for me.
I want to point out what Hammer does, here. Restoring from backup isn’t new – it is in fact probably one of the most basic and necessary of system administration duties. However, Hammer makes it so easy that the incremental work of using it falls to almost nothing. There’s no extra preparation or syntax to learn for retrieval, which is wonderful. Hammer’s easy fix has helped me out several times now, saving me time that, while probably still successful with any other backup system, would have been taken up just restoring things back to normal.
How about when somebody wants to delete something *permanently* (a.k.a. secure delete) from Hammer. Is this possible or everything can be recovered (via hammer or via other recovery tools)?
if the snapshots that contain it are removed, by hand or through normal aging in the setup for that PFS, that’ll get rid of it. Not a perfect solution in this case.
There isn’t an automatic way to purge a given file or files from all histories, but that would definitely be useful. “hammer purge-history”, perhaps?