I appear to be seeing the performance of a local ZFS file system degrading
over a short period of time.
My system configuration:
32 bit Athlon 1800+ CPU
1 Gbyte of RAM
Solaris 10 U6
SunOS filer 5.10 Generic_137138-09 i86pc i386 i86pc
2x250 GByte Western Digital WD2500JB IDE hard drives
1 zfs pool (striped with the two drives, 449 GBytes total)
1 hard drive has an 8 Gbyte UFS slice holding the OS root filesystem
My test consists of reading a single 2.3 Gbyte file using 'dd'. Immediately
after booting the system, I am seeing a read speed of nearly 100 Mbyte per sec.
This is wonderful and shows that the ZFS striping is giving a performance
boost as the maximum data rate from each drive is much lower than that -
somewhere around 60 Mbytes/sec. Unfortunately if I rerun the test multiple
times, the performance degrades. By the 18th time (about 10 minutes later)
the test is run, the performance is down to 54 Mbyte/sec. It is
interesting to note that the read performance of the UFS root filesystem has
not degraded during the above testing. The large file read performance of
the root UFS filesystem remains constant at 58 Mbytes.
I'm running a fresh install of sol-10-u6-ga1-x86-dvd.iso. The only processes
running on the system are the standard ones that happen with a fresh install.
Does anyone know if this performance degradation is normal? If not, does
anyone have hints on what I should do to track down the problem.
Thanks.
Ray
----------The log of my runs is shown below------------
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 23.8
user 0.0
sys 11.1
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 24.5
user 0.0
sys 8.9
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 27.4
user 0.0
sys 8.8
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 26.9
user 0.0
sys 8.4
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 32.0
user 0.0
sys 8.5
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 31.4
user 0.0
sys 8.6
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 33.2
user 0.0
sys 8.8
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 34.1
user 0.0
sys 8.9
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 35.9
user 0.0
sys 8.9
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 36.8
user 0.0
sys 8.7
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 38.1
user 0.0
sys 8.9
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 38.4
user 0.0
sys 8.9
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 39.4
user 0.0
sys 9.0
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 40.3
user 0.0
sys 8.9
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 40.6
user 0.0
sys 9.0
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 41.3
user 0.0
sys 9.0
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 42.2
user 0.0
sys 9.0
# time dd if=big2 of=/dev/null bs=1024k
2201+1 records in
2201+1 records out
real 42.4
user 0.0
sys 9.2
#
--
This message posted from opensolaris.org
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
