iostat's "kr/s" and "kw/s" versus actual timed throughput descrepincies?
2007-12-25 2:34:00
can explain to me.
when doing a "mkfile" to 2 different disk subsystems (emc and internal sun
disks) I an seeing what I think is weird behavior.
I can create a 1gb file on the EMC and the "kw/s" are around "9050" and it
takes 1min 10sec
then I create a 1gb file on the internal drives and the "kw/s" are around
"19950" across the single controller, and it takes around 57 seconds.
since the sun drive is averaging more that TWICE the "kw/s", should it not
have a time that is TWICE as fast?
p.s. this machine is solaris 2.6/vxfs.
test data:
time mkfile 1024m test1 /emc-symmetrix/filesystem
0.25u 43.47s 1:10.02 62.4%
and the "iostat -x 3 1000" output looks consistantly like this:
extended device statistics
device r/s w/s kr/s kw/s wait actv svc_t %w %b
sd531 0.0 183.7 0.0 9050.7 10.5 7.9 100.6 95 100
then I run:
time mkfile 1024m test2 /sun450-internal/filesystem
0.17u 43.53s 0:57.68 75.7%
and the "iostat -x 3 1000" output looks consistantly like this:
extended device statistics
device r/s w/s kr/s kw/s wait actv svc_t %w %b
sd65 0.0 328.0 0.0 19950.0 0.4 10.9 34.5 14 99
-alex
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