[BlueOnyx:22585] Help please with mysqld

[Colin Jack]

One of our VPS has suddenly started running slowly.
Initial concern was that we may have a spam flood but no.

top - 12:06:49 up 1 day, 22:57,  1 user,  load average: 5.27, 5.12, 5.27
Tasks: 153 total,   2 running, 150 sleeping,   0 stopped,   1 zombie
Cpu(s): 15.4%us,  1.7%sy,  0.0%ni, 67.5%id, 15.5%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  12582912k total, 10093908k used,  2489004k free,        0k buffers
Swap:  4194304k total,   292380k used,  3901924k free,  7218020k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 8410 mysql     20   0 1589m  34m 4480 S 170.2  0.3   3649:55 mysqld
 4275 michrow   20   0  296m  88m 3136 R 99.9  0.7   0:07.10 spamd
 3830 admserv   20   0  435m  20m 5352 D  1.0  0.2   0:00.22 httpd.admsrv
 3406 root      20   0 36348 2628 1872 S  0.7  0.0   0:00.29 auth
 3326 root      20   0  113m 1400  984 D  0.3  0.0   0:00.16 tar
 3327 root      20   0 1212m 9.8m  572 S  0.3  0.1   0:02.24 pigz
 3686 root      20   0 15032 1292  944 R  0.3  0.0   0:00.71 top
 8614 tomcat    20   0 5577m  50m 2972 S  0.3  0.4   4:26.72 java
 9664 root      20   0  139m 3232 1024 S  0.3  0.0   4:14.46 sec

MySQL seems to have gone crazy!

I would appreciate some help in tracking down what is causing this.

5208R - fully up to date.
Tried rebooting which clears it briefly.

Thanks

Colin