Re: [OpenIndiana-discuss] Scrub on single ZFS volume
On Mon, 23 Oct 2023, Michelle wrote: OK - so basically, even though it can't repair damage, (as there is no parity) at least it can flag up that checksums didn't check. I just noticed this email now. In addition to ordinary user file data, zfs stores redundant metadata so if a bit of the metadata is corrupt, it may be able to repair it using a good copy. This is a reason to still scrub single-disk pools. A reason to scrub single-disk pools periodically is to help discover when the disk is going bad so it can be replaced before there is much data loss. Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer,http://www.GraphicsMagick.org/ Public Key, http://www.simplesystems.org/users/bfriesen/public-key.txt ___ openindiana-discuss mailing list openindiana-discuss@openindiana.org https://openindiana.org/mailman/listinfo/openindiana-discuss
Re: [OpenIndiana-discuss] Scrub on single ZFS volume
On Mon, 2023-10-23 at 10:30 +0200, Marcel Telka wrote: > > Does a scrub still make sense when there isn't any parity? > Yes > From the zpool man page: > > zpool scrub [-s | -p] pool... > Begins a scrub or resumes a paused scrub. The scrub > examines all > data in the specified pools to verify that it checksums > correctly. > For replicated (mirror or raidz) devices, ZFS > automatically repairs > any damage discovered during the scrub. The zpool > status command > reports the progress of the scrub and summarizes the > results of the > scrub upon completion. > OK - so basically, even though it can't repair damage, (as there is no parity) at least it can flag up that checksums didn't check. ___ openindiana-discuss mailing list openindiana-discuss@openindiana.org https://openindiana.org/mailman/listinfo/openindiana-discuss
Re: [OpenIndiana-discuss] Scrub on single ZFS volume
On Mon, Oct 23, 2023 at 09:14:05AM +0100, Michelle wrote: > I'm having problems getting this question answered via the usual google > search, so I thought I'd ask here. I'm surprised google is unable to find the zpool man page available at https://illumos.org/man/8/zpool. Maybe you should try different search tool, or simply run `man zpool`? > The question is... how do I check the integrity of the data on the > single backup volume? zpool scrub > Does a scrub still make sense when there isn't any parity? Yes. >From the zpool man page: zpool scrub [-s | -p] pool... Begins a scrub or resumes a paused scrub. The scrub examines all data in the specified pools to verify that it checksums correctly. For replicated (mirror or raidz) devices, ZFS automatically repairs any damage discovered during the scrub. The zpool status command reports the progress of the scrub and summarizes the results of the scrub upon completion. -- +---+ | Marcel Telka e-mail: mar...@telka.sk | |homepage: http://telka.sk/ | +---+ ___ openindiana-discuss mailing list openindiana-discuss@openindiana.org https://openindiana.org/mailman/listinfo/openindiana-discuss
