On Fri, Jun 04, 2010 at 12:37:01PM -0700, Ray Van Dolson wrote: > On Fri, Jun 04, 2010 at 11:16:40AM -0700, Brandon High wrote: > > On Fri, Jun 4, 2010 at 9:30 AM, Ray Van Dolson <rvandol...@esri.com> wrote: > > > The ISO's I'm testing with are the 32-bit and 64-bit versions of the > > > RHEL5 DVD ISO's. While both have their differences, they do contain a > > > lot of similar data as well. > > > > Similar != identical. > > > > Dedup works on blocks in zfs, so unless the iso files have identical > > data aligned at 128k boundaries you won't see any savings. > > > > > If I explode both ISO files and copy them to my ZFS filesystem I see > > > about a 1.24x dedup ratio. > > > > Each file starts a new block, so the identical files can be deduped. > > > > -B > > Makes sense. So, as someone else suggested, decreasing my block size > may improve the deduplication ratio. > > recordsize I presume is the value to tweak?
Yes, but I'd not expect that much commonality between 32-bit and 64-bit Linux ISOs... Do the same check again with the ISOs "exploded", as you say. Nico -- _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
