What iowait values are ok?

Posted by alfish on Server Fault See other posts from Server Fault or by alfish
Published on 2011-08-05T02:17:25Z Indexed on 2011/11/14 1:53 UTC
Read the original article Hit count: 504

Filed under:

mysql

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bottleneck

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iostat

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iowait

I am trying to find the bottleneck of a server running a fairly busy php/mysql site. My first culprit was io but iostat shows that on average iowait consumes only %3.60 of cpu time. here is the complete result of issuing iostat:

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          65.78    0.00    8.52    3.60    0.00   22.10

Device:            tps   Blk_read/s   Blk_wrtn/s   Blk_read   Blk_wrtn
sda              42.36       138.28      1754.70  408630278 5185216128

So I am wondering if the iowait is within acceptable range, and if not, whether switching from SATA to SSD would dramatically reduce it?

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