On Sun, 16 Mar 2008, Richard Elling wrote:
>
> But where is the bottleneck? iostat will show bottlenecks in the
> physical disks and channels. vmstat or mpstat will show the
> bottlenecks in cpus. To see if the app is the bottleneck will
> require some analysis of the app itself. Is it spending its time
> blocked on I/O?
The application is spending almost all the time blocked on I/O. I see
that the number of device writes per second seems pretty high. The
application is doing I/O in 128K blocks. How many IOPS does a modern
300GB 15K RPM SAS drive typically deliver? Of course the IOPS
capacity depends on if the access is random or sequential. At the
application level, the access is completely sequential but ZFS is
likely doing some extra seeks.
iostat output (atime=off):
extended device statistics
device r/s w/s Mr/s Mw/s wait actv svc_t %w %b
sd0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0
sd1 0.0 0.0 0.0 0.0 0.0 0.0 2.8 0 0
sd2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0
sd10 80.4 170.7 10.0 19.9 0.0 9.2 36.5 0 54
sd11 82.1 170.2 10.2 20.0 0.0 13.3 52.9 0 71
sd12 79.3 168.3 9.9 20.0 0.0 13.1 53.1 0 69
sd13 80.6 173.0 10.0 19.9 0.0 9.3 36.7 0 56
sd14 80.9 167.8 10.1 20.0 0.0 13.4 53.8 0 70
sd15 77.7 168.7 9.7 19.9 0.0 9.1 37.1 0 52
sd16 77.3 170.6 9.6 20.0 0.0 13.3 53.7 0 70
sd17 76.4 168.2 9.5 20.0 0.0 9.1 37.2 0 52
sd18 76.7 172.2 9.5 19.9 0.0 13.5 54.2 0 70
sd19 83.8 173.2 10.4 20.0 0.0 13.7 53.4 0 74
sd20 73.3 174.3 9.1 20.0 0.0 9.1 36.9 0 56
sd21 75.3 170.2 9.4 20.0 0.0 13.2 53.9 0 69
nfs1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0
% mpstat
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 288 1 189 1018 413 815 26 102 88 0 3046 3 3 0 94
1 185 1 180 634 1 830 43 111 74 0 3117 3 2 0 94
2 284 1 183 521 6 617 27 98 67 0 4954 4 3 0 93
3 176 1 239 748 353 555 25 76 62 0 3933 4 3 0 93
Bob
======================================
Bob Friesenhahn
[EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/
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