Server load high, CPU idle. NFS the cause?
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by Mech Software
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Published on 2010-03-09T01:35:04Z
Indexed on
2010/03/09
1:37 UTC
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I am running into a scenario where I'm seeing a high server load (sometimes upwards of 20 or 30) and a very low CPU usage (98% idle). I'm wondering if these wait states are coming as part of an NFS filesystem connection. Here is what I see in VMStat
procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu------
r b swpd free buff cache si so bi bo in cs us sy id wa st
2 1 0 1298784 0 0 0 0 16 5 0 9 1 1 97 2 0
0 1 0 1308016 0 0 0 0 0 0 0 3882 4 3 80 13 0
0 1 0 1307960 0 0 0 0 120 0 0 2960 0 0 88 12 0
0 1 0 1295868 0 0 0 0 4 0 0 4235 1 2 84 13 0
6 0 0 1292740 0 0 0 0 0 0 0 5003 1 1 98 0 0
4 0 0 1300860 0 0 0 0 0 120 0 11194 4 3 93 0 0
4 1 0 1304576 0 0 0 0 240 0 0 11259 4 3 88 6 0
3 1 0 1298952 0 0 0 0 0 0 0 9268 7 5 70 19 0
3 1 0 1303740 0 0 0 0 88 8 0 8088 4 3 81 13 0
5 0 0 1304052 0 0 0 0 0 0 0 6348 4 4 93 0 0
0 0 0 1307952 0 0 0 0 0 0 0 7366 5 4 91 0 0
0 0 0 1307744 0 0 0 0 0 0 0 3201 0 0 100 0 0
4 0 0 1294644 0 0 0 0 0 0 0 5514 1 2 97 0 0
3 0 0 1301272 0 0 0 0 0 0 0 11508 4 3 93 0 0
3 0 0 1307788 0 0 0 0 0 0 0 11822 5 3 92 0 0
From what I can tell when the IO goes up the waits go up. Could NFS be the cause here or should I be worried about something else? This is a VPS box on a fiber channel SAN. I'd think the bottleneck wouldn't be the SAN. Comments?
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