ZFS on Linux
fsck.zfs - Dummy ZFS filesystem checker.
fsck.zfs [options] <dataset>
fsck.zfs is a shell stub that does nothing and always returns true. It is installed by ZoL because some Linux distributions expect a fsck helper for all filesystems.
|All options and the dataset are ignored.|
ZFS datasets are checked by running zpool scrub on the containing pool. An individual ZFS dataset is never checked independently of its pool, which is unlike a regular filesystem.
On some systems, if the dataset is in a degraded pool, then it might be appropriate for fsck.zfs to return exit code 4 to indicate an uncorrected filesystem error.
Similarly, if the dataset is in a faulted pool and has a legacy /etc/fstab record, then fsck.zfs should return exit code 8 to indicate a fatal operational error.
Darik Horn <dajhorn>.