Yes, and the
vmstat showed that the CPU is even idle while disk
I/O is rather high. It's not mysql doing nothing. It's mysql
waiting for the disk. The new server, how many disks will it
have?
Breakthrough! Improving disk throughput for the database would probably do
wonders for Wikipedia performance.
Well it's not quite that simple--just because the machine is
waiting for disk I/O, that doesn't mean the speed of the disks
is necessarily the problem. Memory use could be affecting the
ability to cache, interference between Apache filesystem access
and MySQL access could be making seeks inefficient, etc.
But that does bring up the point that when we get the new server,
there's really nothing constraining which one we use for the
database and which for Apache, so we can make that decision
based on the hardware available to each.
--
Lee Daniel Crocker <lee(a)piclab.com> <http://www.piclab.com/lee/>
"All inventions or works of authorship original to me, herein and past,
are placed irrevocably in the public domain, and may be used or modified
for any purpose, without permission, attribution, or notification."--LDC