On Wed, Dec 16, 2009 at 7:46 PM, Darren J Moffat <darr...@opensolaris.org> wrote: > Andrey Kuzmin wrote: >> >> On Wed, Dec 16, 2009 at 7:25 PM, Kjetil Torgrim Homme >> <kjeti...@linpro.no> wrote: >>> >>> Andrey Kuzmin <andrey.v.kuz...@gmail.com> writes: >>>> >>>> Yet again, I don't see how RAID-Z reconstruction is related to the >>>> subject discussed (what data should be sha256'ed when both dedupe and >>>> compression are enabled, raw or compressed ). sha256 has nothing to do >>>> with bad block detection (may be it will when encryption is >>>> implemented, but for now sha256 is used for duplicate candidates >>>> look-up only). >>> >>> how do you think RAID-Z resilvering works? please correct me where I'm >>> wrong. >> >> Resilvering has noting to do with sha256: one could resilver long >> before dedupe was introduced in zfs. > > SHA256 isn't just used for dedup it is available as one of the checksum > algorithms right back to pool version 1 that integrated in build 27.
'One of' is the key word. And thanks for code pointers, I'll take a look. Regards, Andrey > > SHA256 is also used to checksum the pool uberblock. > > This means that SHA256 is used during resilvering and especially so if you > have checksum=sha256 for your datasets. > > If you still don't believe me check the source code history: > > http://src.opensolaris.org/source/history/onnv/onnv-gate/usr/src/uts/common/fs/zfs/zio_checksum.c > http://src.opensolaris.org/source/history/onnv/onnv-gate/usr/src/uts/common/fs/zfs/sha256.c > > Look at the date when that integrated 31st October 2005. > > In case you still doubt me look at the fix I just integrated today: > > http://mail.opensolaris.org/pipermail/onnv-notify/2009-December/011090.html > > > -- > Darren J Moffat > _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
