On 2021/04/16 4:37, Sitsofe Wheeler wrote:
On Thu, 15 Apr 2021 at 03:49, Nakajima Akira
<nakajima.akira@xxxxxxxxxxxx <mailto:nakajima.akira@xxxxxxxxxxxx>> wrote:
Hi.
Sorry. Due to my company's email sender domain restrictions,
it could not be sent to gmail.
Above is the result on unencrypted ext4/xfs.
Similar results are obtained on encrypted ext4/xfs.
Since the memory is 24GB, I tried it with 72GB + α = 76GB.
# fio -filename=/testfile -direct=1 -ioengine=libaio -rw=write -bs=1m
-size=76G -runtime=60 -numjobs=1 -group_reporting -name=a
write: IOPS=195, BW=195MiB/s (205MB/s)(11.4GiB/60023msec)
# fio -filename=/testfile -direct=1 -ioengine=libaio -rw=write -bs=1m
-size=76G -runtime=60 -numjobs=10 -group_reporting -name=a
write: IOPS=1622, BW=1622MiB/s (1701MB/s)(95.1GiB/60042msec)
# fio -filename=/testfile -direct=1 -ioengine=libaio -rw=write -bs=1m
-size=76G -runtime=300 -numjobs=10 -group_reporting -name=a
write: IOPS=1879, BW=1880MiB/s (1971MB/s)(551GiB/300004msec)
Ah, that numjobs value is REALLY important for the type of job file
you have! Using numjobs on the same filename can lead to reuse of the
same area (think job 1 and job 2 writing the same blocks in lockstep)
which may in turn lead to not all I/Os being sent down to the disk if
they are close enough together. This may make a nonsense of your
benchmark...
Up to numjobs = about 10, it increases in proportion to the value of
numjobs.
--
Sitsofe
Hi.
Now I tried, but these had the same results.
(twice as much as numjobs=1)
-filename=/mnt/test1:/mnt/test2
-filename=/dev/sdb (after umount /mnt)
# fio -filename=xxx -direct=1 -ioengine=libaio -rw=write -bs=1m -size=8G
-runtime=60 -numjobs=2 -group_reporting -name=a
Using -directory instead of -filename is only way to get correct result?
Thanks.
Nakajima.
