Some one asked me about ZFS resilver ..
When we replace a disk does resilver do scrub of the pool ?
It is really a good question.
First of all resilver and scrub are mutually exclusive operations i.e. both will not happen at the same time.
But remember resilver itself is a kind of scrub.
When a disk is replaced ZFS resilver operation copies good data to the new device so indirectly we are doing a scrub i.e. reading and validating good data.
Resilver copies only the amount of data that is out of sync.
If resilver is interrupted then if can resume from the same point where it left.
** Resilver is withing affected vdev i.e. it checks data withing the same VDEV and other vdevs will not be checked. If you have more than one vdev then yes there is a need of separate scrub of whole pool
** Resilver triggers a scrub if it encounters too many checksum errors.
When we replace a disk does resilver do scrub of the pool ?
It is really a good question.
First of all resilver and scrub are mutually exclusive operations i.e. both will not happen at the same time.
But remember resilver itself is a kind of scrub.
When a disk is replaced ZFS resilver operation copies good data to the new device so indirectly we are doing a scrub i.e. reading and validating good data.
Resilver copies only the amount of data that is out of sync.
If resilver is interrupted then if can resume from the same point where it left.
** Resilver is withing affected vdev i.e. it checks data withing the same VDEV and other vdevs will not be checked. If you have more than one vdev then yes there is a need of separate scrub of whole pool
** Resilver triggers a scrub if it encounters too many checksum errors.
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