I have a cpanel LAMP dedicated server and I've been having load problems the last 2 days.
This is what my top looks like (sorted by M):
top - 14:26:04 up 1 day, 1:08, 2 users, load average: 33.10, 36.63, 38.92
Tasks: 359 total, 1 running, 355 sleeping, 1 stopped, 2 zombie
Cpu(s): 4.2%us, 0.8%sy, 0.0%ni, 13.6%id, 81.0%wa, 0.0%hi, 0.3%si, 0.0%st
Mem: 1034896k total, 998084k used, 36812k free, 8716k buffers
Swap: 2040212k total, 1606552k used, 433660k free, 87388k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
5088 mysql 15 0 336m 106m 3868 S 1.3 10.6 310:15.37 mysqld
15797 nobody 18 0 331m 65m 1988 S 3.0 6.4 0:04.64 httpd
15635 nobody 19 0 371m 63m 1840 S 0.0 6.3 0:00.88 httpd
15664 nobody 18 0 374m 63m 1832 S 1.3 6.2 0:00.43 httpd
15769 nobody 19 0 336m 59m 1700 S 0.0 5.9 0:00.29 httpd
15721 nobody 18 0 324m 59m 1732 S 1.0 5.9 0:00.29 httpd
15697 nobody 18 0 304m 59m 1692 S 0.0 5.8 0:00.46 httpd
iostat is:
Linux 2.6.18-164.15.1.el5 (hostname) 05/20/2011
avg-cpu: %user %nice %system %iowait %steal %idle
21.93 0.33 4.91 12.03 0.00 60.79
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 65.16 1069.51 1285.65 96981151 116580545
sda1 0.00 0.03 0.00 3023 31
sda2 18.59 444.95 159.37 40347535 14451402
sda3 7.15 129.47 113.45 11740498 10287608
sda4 0.00 0.00 0.00 6 0
sda5 1.25 12.88 44.49 1167658 4034632
sda6 3.92 11.25 525.79 1020250 47677744
sda7 5.56 108.71 96.29 9857739 8731832
sda8 28.70 362.20 346.25 32843994 31397296
Mysql seems to have many processes running (is constantly on "Too many connections"). None of my sites seems to have too much traffic and I see no specific queries taking more than others.
Could you please propose a way to debug / deal with this situation?
iostat <interval>
where <interval> is your time interval in seconds to average the data. Using the -x parameter to iostat further helps debugging as it provides you with other interesing data like queue length, service times and device utilization. To get hold of the process that is doing the most I/O useiotop