Post #2382408
2026-05-07 13:19 UTC
@mwl@io.mwl.io @mdione@en.osm.town @grumpybozo@toad.social @djfiander@code4lib.social @b0rk@social.jvns.ca I reiterate that scrub *does not* do what fsck does. It *only* checks block checksums. It does not check for semantic errors in the on-disk data structures. This is a design error and an unforgivable act of hubris by the ZFS developers.
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Replies (1)
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@zwol@masto.hackers.town 2026-05-07 13:20
@mwl@io.mwl.io @mdione@en.osm.town @grumpybozo@toad.social @djfiander@code4lib.social @b0rk@social.jvns.ca That said, the *point* of scrub is the same as for RAID: it checks *all* the block checksums. Ordinary FS operations only check block checksums on blocks that are referenced by those operations. If a disk sector goes bad within a file that's rarely accessed, and scrub is not being run periodically, nothing will notice until the next time the file *is* accessed, which might be too late to recover it. (2/2)