Re: [zfs-discuss] ZFS Perfomance
On Apr 14, 2010, at 11:10 PM, Daniel Carosone wrote: > On Wed, Apr 14, 2010 at 09:58:50AM -0700, Richard Elling wrote: >> On Apr 14, 2010, at 8:57 AM, Yariv Graf wrote: >> >>> From my experience dealing with > 4TB you stop writing after 80% of zpool >>> utilization >> >> YMMV. I have routinely completely filled zpools. There have been some >> improvements in performance of allocations when free space gets low in >> the past 6-9 months, so later releases are more efficient. > > Some weeks ago, I read with interest an excellent discussion of > changes resulting in performance benefits for the fishworks platform, > from Roch Bourbonnais. > > After all the analysis, three key changes are described in the > penultimate paragraph. The first two of these basically adjust > thresholds for existing behavioual changes (e.g the switch from > first-fit to best-fit); the last is an actual code change. > > I meant to ask at the time, and never followed up to do so, whether: > - these changes are also/yet in onnv-gate zfs > - which builds, if so > - whether the altered thresholds are accessible as tunables, for > older builds/in the meantime. There are several b114: 6596237 Stop looking and start ganging b129: 6869229 zfs should switch to shiny new metaslabs more frequently b138: 6917066 zfs block picking can be improved there are probably a few more... -- richard > I've just added the above as a comment on the blog post, in the > hopes of attracting Roch's attention there. There have been recent > commits go by (>b134) that seem promising too. > > -- > Dan. 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
Re: [zfs-discuss] ZFS Perfomance
On Wed, Apr 14, 2010 at 09:58:50AM -0700, Richard Elling wrote: > On Apr 14, 2010, at 8:57 AM, Yariv Graf wrote: > > > From my experience dealing with > 4TB you stop writing after 80% of zpool > > utilization > > YMMV. I have routinely completely filled zpools. There have been some > improvements in performance of allocations when free space gets low in > the past 6-9 months, so later releases are more efficient. Some weeks ago, I read with interest an excellent discussion of changes resulting in performance benefits for the fishworks platform, from Roch Bourbonnais. After all the analysis, three key changes are described in the penultimate paragraph. The first two of these basically adjust thresholds for existing behavioual changes (e.g the switch from first-fit to best-fit); the last is an actual code change. I meant to ask at the time, and never followed up to do so, whether: - these changes are also/yet in onnv-gate zfs - which builds, if so - whether the altered thresholds are accessible as tunables, for older builds/in the meantime. I've just added the above as a comment on the blog post, in the hopes of attracting Roch's attention there. There have been recent commits go by (>b134) that seem promising too. -- Dan. pgp40C47xo00o.pgp Description: PGP signature ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS Perfomance
Richard Elling wrote: On Apr 14, 2010, at 8:57 AM, Yariv Graf wrote: From my experience dealing with > 4TB you stop writing after 80% of zpool utilization YMMV. I have routinely completely filled zpools. There have been some improvements in performance of allocations when free space gets low in the past 6-9 months, so later releases are more efficient. -- richard I would echo Richard here, and add that it also seems to be dependent on the usage characteristics. That is, using in a write-mostly (or, write-almost-exclusively) form seems to result in no problems filling a pool to 100% - so, if you're going to use the zpool for (say) storing your DVD images (or other media-server applications), then go ahead, and plan to fill the pool up. On the other hand, doing lots of write/erase stuff (particularly with a wide mix of file sizes) does indeed seem to cause performance to drop off rather quickly once 80% (or thereabouts) capacity is reached. For instance - I routinely back up my local developers' workstation's disks to a ZFS box using rsync, rapidly changing the contents of my zpool each night (as I also expire old backups more than 1 week old). That machine hits a brick wall on performance at about 82% full (6-disk 250GB 7200RPM SATA in a raidz1). -- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS Perfomance
On Apr 14, 2010, at 8:57 AM, Yariv Graf wrote: > From my experience dealing with > 4TB you stop writing after 80% of zpool > utilization YMMV. I have routinely completely filled zpools. There have been some improvements in performance of allocations when free space gets low in the past 6-9 months, so later releases are more efficient. -- richard > > 10 > > On Apr 14, 2010, at 6:53 PM, "eXeC001er" wrote: > >> 20 % - it is big size on for large volumes. right ? >> >> >> 2010/4/14 Yariv Graf >> Hi >> Keep below 80% >> >> 10 >> >> On Apr 14, 2010, at 6:49 PM, "eXeC001er" wrote: >> >>> Hi All. >>> >>> How many disk space i need to reserve for save ZFS perfomance ? >>> >>> any official doc? >>> >>> Thanks. >>> ___ >>> zfs-discuss mailing list >>> zfs-discuss@opensolaris.org >>> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss >> > ___ > 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
Re: [zfs-discuss] ZFS Perfomance
From my experience dealing with > 4TB you stop writing after 80% of zpool utilization 10 On Apr 14, 2010, at 6:53 PM, "eXeC001er" wrote: 20 % - it is big size on for large volumes. right ? 2010/4/14 Yariv Graf Hi Keep below 80% 10 On Apr 14, 2010, at 6:49 PM, "eXeC001er" wrote: Hi All. How many disk space i need to reserve for save ZFS perfomance ? any official doc? Thanks. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS Perfomance
20 % - it is big size on for large volumes. right ? 2010/4/14 Yariv Graf > Hi > Keep below 80% > > 10 > > On Apr 14, 2010, at 6:49 PM, "eXeC001er" wrote: > > Hi All. > > How many disk space i need to reserve for save ZFS perfomance ? > > any official doc? > > Thanks. > > ___ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS Perfomance
Hi Keep below 80% 10 On Apr 14, 2010, at 6:49 PM, "eXeC001er" wrote: Hi All. How many disk space i need to reserve for save ZFS perfomance ? any official doc? Thanks. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
