Dan Naumov
2009-Jun-17 07:34 UTC
ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates
I am wondering if the numbers I am seeing is something expected or is
something broken somewhere. Output of bonnie -s 1024:
on UFS2 + SoftUpdates:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
1024 56431 94.5 88407 38.9 77357 53.3 64042 98.6 644511 98.6
23603.8 243.3
on ZFS:
-------Sequential Output-------- ---Sequential Input-- --Random--
-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
1024 22591 53.7 45602 35.1 14770 13.2 45007 83.8 94595 28.0 102.2 1.2
atom# cat /boot/loader.conf
vm.kmem_size="1024M"
vm.kmem_size_max="1024M"
vfs.zfs.arc_max="96M"
The test isn't completely fair in that the test on UFS2 is done on a
partition that resides on the first 16gb of a 2tb disk while the zfs
test is done on the enormous 1,9tb zfs pool that comes after that
partition (same disk). Can this difference in layout make up for the
huge difference in performance or is there something else in play? The
system is an Intel Atom 330 dualcore, 2gb ram, Western Digital Green
2tb disk. Also what would be another good way to get good numbers for
comparing the performance of UFS2 vs ZFS on the same system.
Sincerely,
- Dan Naumov
Joe Koberg
2009-Jun-17 16:08 UTC
ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates
The difference in layout can easily explain a 2x difference in sequential transfer performance. I seriously doubt your disk is really getting 23K seeks/s done in the UFS case - 100/s sounds much more reasonable for real hardware. Perhaps the results of caching? Joe Koberg Dan Naumov wrote:> I am wondering if the numbers I am seeing is something expected or is > something broken somewhere. Output of bonnie -s 1024: > > on UFS2 + SoftUpdates: > > -------Sequential Output-------- ---Sequential Input-- --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU > 1024 56431 94.5 88407 38.9 77357 53.3 64042 98.6 644511 98.6 23603.8 243.3 > > on ZFS: > > -------Sequential Output-------- ---Sequential Input-- --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU > 1024 22591 53.7 45602 35.1 14770 13.2 45007 83.8 94595 28.0 102.2 1.2 > > > atom# cat /boot/loader.conf > vm.kmem_size="1024M" > vm.kmem_size_max="1024M" > vfs.zfs.arc_max="96M" > > The test isn't completely fair in that the test on UFS2 is done on a > partition that resides on the first 16gb of a 2tb disk while the zfs > test is done on the enormous 1,9tb zfs pool that comes after that > partition (same disk). Can this difference in layout make up for the > huge difference in performance or is there something else in play? The > system is an Intel Atom 330 dualcore, 2gb ram, Western Digital Green > 2tb disk. Also what would be another good way to get good numbers for > comparing the performance of UFS2 vs ZFS on the same system. > > > Sincerely, > - Dan Naumov > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" > >
Dan Nelson
2009-Jun-17 16:11 UTC
ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates
In the last episode (Jun 17), Dan Naumov said:> I am wondering if the numbers I am seeing is something expected or is > something broken somewhere. Output of bonnie -s 1024: > > on UFS2 + SoftUpdates: > > -------Sequential Output-------- ---Sequential Input-- --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU > 1024 56431 94.5 88407 38.9 77357 53.3 64042 98.6 644511 98.6 23603.8 243.3The insane sequential input K/sec and random seeks/sec values indicate that your entire test file was cached in memory. Try a larger file (at least 2x your installed RAM).> on ZFS: > > -------Sequential Output-------- ---Sequential Input-- --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU > 1024 22591 53.7 45602 35.1 14770 13.2 45007 83.8 94595 28.0 102.2 1.2 >-- Dan Nelson dnelson@allantgroup.com
Ronald Klop
2009-Jun-17 23:51 UTC
ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates
On Wed, 17 Jun 2009 09:34:02 +0200, Dan Naumov <dan.naumov@gmail.com> wrote:> I am wondering if the numbers I am seeing is something expected or is > something broken somewhere. Output of bonnie -s 1024: > > on UFS2 + SoftUpdates: > > -------Sequential Output-------- ---Sequential Input-- > --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- > --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU > /sec %CPU > 1024 56431 94.5 88407 38.9 77357 53.3 64042 98.6 644511 98.6 > 23603.8 243.3 > > on ZFS: > > -------Sequential Output-------- ---Sequential Input-- > --Random-- > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- > --Seeks--- > Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU > /sec %CPU > 1024 22591 53.7 45602 35.1 14770 13.2 45007 83.8 94595 28.0 > 102.2 1.2 > > > atom# cat /boot/loader.conf > vm.kmem_size="1024M" > vm.kmem_size_max="1024M" > vfs.zfs.arc_max="96M"Isn't 96M for ARC really small? Mine is 860M. vfs.zfs.arc_max: 860072960 kstat.zfs.misc.arcstats.size: 657383376 I think the UFS2 cache is much bigger which makes a difference in your test. Ronald.