Hi!
I am using Gentoo Linux on XFS root filesystem on a number of machines,
where some are P4 based i686, and some new are Intel Core 2 Duo based
x86_64 based.
When the new x86_64 based machines were put into service, we noticed
that they are extremely slow on file io. I have now created two test
partitions, each 5G in size, on the same disk. One is xfs and one is
ext3, both filesystems created with default options. My simple test is
to rsync our local portage tree to the 5G partition:
=====================================================================
tmpc-masv2 xfs # time rsync -r --delete rsync://devsrv/portage portage
real 5m55.037s
user 0m1.291s
sys 0m10.352s
======================================================================
tmpc-masv2 ext3 # time rsync -r --delete rsync://devsrv/portage portage
real 0m28.943s
user 0m1.095s
sys 0m5.384s
I have repeated this a number of times to make sure caching on the
server does not interfere, with about the same results every time.
Any idea why XFS appears to be 12 times slower than ext3 on the 64-bit
machine?
I have also some statistics from bonnie++:
XFS:
Version 1.93c ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
tmpc-masv2 4G 929 99 48914 8 23036 3 1872 96 50322 4 162.0 1
Latency 8913us 1675ms 492ms 54567us 161ms 503ms
Version 1.93c ------Sequential Create------ --------Random Create--------
tmpc-masv2 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 3241 13 +++++ +++ 3541 13 3729 14 +++++ +++ 1001 4
Latency 60600us 80us 34066us 82412us 22us 269ms
EXT3:
Version 1.93c ------Sequential Output------ --Sequential Input- --Random-
Concurrency 1 -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP
tmpc-masv2 4G 581 98 43340 9 22933 4 2435 96 50829 4 153.5 1
Latency 56412us 2111ms 1885ms 41179us 101ms 690ms
Version 1.93c ------Sequential Create------ --------Random Create--------
tmpc-masv2 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP
16 31286 38 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
Latency 11233us 145us 165us 7555us 8us 40us
As it looks here, xfs performs ok (but not as good as expected) on large
files, but creating and deleting files is extremely slow.
The machine these test run on uses Gentoo kernel sources
2.6.23-gentoo-r1 (also tested with 2.6.22-gentoo-r8). xfsprogs is 2.9.4.
/Johan Andersson
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