On Mar 25, 2010, at 7:25 PM, antst wrote: > I have two storages, both on snv133. Both filled with 1TB drives. > 1) stripe over two raidz vdevs, 7 disks in each. In total avalable size is > (7-1)*2=12TB > 2) zfs pool over HW raid, also 12TB. > > Both storages keeps the same data with minor differences. First pool keeps 24 > hourly snapshots + 7 daily snapshots. Second one (backup) keeps only daily > snapshots, but for longer period (2 weeks for now).
Good idea :-) > But they reports strangely different sizes which can't be explained by > differences in snapshots I believe. > > 1) > # zpool list export > NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT > export 12.6T 3.80T 8.82T 30% 1.00x ONLINE - > > # zfs list export > NAME USED AVAIL REFER MOUNTPOINT > export 3.24T 7.35T 40.9K /export > > 2) > # zpool list export > NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT > export 12.6T 3.19T 9.44T 25% 1.00x ONLINE - > > # zfs list export > NAME USED AVAIL REFER MOUNTPOINT > export 3.19T 9.24T 25K /export > > As we see, both pools have the same size according to "zpool". Correct. > As we see, for second storage size reported by "zpool list" and sum of used > and avail in "zfs list" are in agreement. Correct. > But for first one, 2TB is missing somehow, sum of USED and avail is 10.6 TB. Correct. To understand this, please see the ZFS FAQ: http://hub.opensolaris.org/bin/view/Community+Group+zfs/faq#HWhydoesntthespacethatisreportedbythezpoollistcommandandthezfslistcommandmatch [richard pauses to look in awe at the aforementioned URL...] -- richard > Also what makes me a bit wonder, is that I would expect more space to be used > on backup pool (more daily snapshots), but if "zfs list" can be explained > that amount taken by hourly snapshots is bigger than amount taken by extra 7 > daily snapshots on backup storage (difference is 50GB which is still pretty > big, taking into account that on backup storage we have also extra 10 gig of > backup of rpool from primary storage), there is no way for this explanation > to be valid for difference in USED reported by "zpool list". 600GB is much > more than any possible difference coming from storing different snapshots, > because our guys just don't produce so much of data daily. Also I tried to > look how much of space is refereed by hourly snapshots - no way to be even > close to 600GB. > > What's wrong there? My main concern, though, is difference between zpool size > and sum of used+avail for zfs on primary storage. 2TB is 2TB! > -- > This message posted from opensolaris.org > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ZFS storage and performance consulting at http://www.RichardElling.com ZFS training on deduplication, NexentaStor, and NAS performance Las Vegas, April 29-30, 2010 http://nexenta-vegas.eventbrite.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
