Welcome to WebmasterWorld Guest from 54.144.126.195

Forum Moderators: bakedjake

Message Too Old, No Replies

Disk I/O Monitoring for Cent 5.6

Disk I/O Monitoring for Cent 5.6

     

Das Capitolin

5:10 am on Aug 17, 2011 (gmt 0)

5+ Year Member



For the past month my Cent 5.6 server has suffered random I/O spikes that last from several minutes to many hours. I'm struggling to find the ideal tool to help track down the culprit, and hope the users here can offer some suggestions.

I've got Webmin installed which tells me basic I/O usage in %, but stops short of pointing out process I/O usage. I've also installed Cacti, but it doesn't appear I can run down the problem with it either. Using the vmstat command (vmstat 1 10) tells me almost nothing useful.

Please offer some guidance.

phranque

6:41 am on Aug 17, 2011 (gmt 0)

WebmasterWorld Administrator phranque is a WebmasterWorld Top Contributor of All Time 10+ Year Member Top Contributors Of The Month



perhaps iostat will provide the information you need.

Das Capitolin

2:34 pm on Aug 17, 2011 (gmt 0)

5+ Year Member



Thank you, but iostat (iostat -d -k -x) only shows me read/write activity on the disk. What I need is to see that information at a process level.

Das Capitolin

2:38 pm on Aug 17, 2011 (gmt 0)

5+ Year Member



sar -b produces roughly the same results, so it won't work either.

bakedjake

2:40 pm on Aug 17, 2011 (gmt 0)

WebmasterWorld Administrator bakedjake is a WebmasterWorld Top Contributor of All Time 10+ Year Member



block_dump is what you're looking for.

Be careful; only use it sparingly for short amounts of time as it generates massive (additional) disk activity.

Enable it with sysctl, then use /var/log/debug to find the culprit. Remember to disable it when you're done!

Das Capitolin

2:52 pm on Aug 17, 2011 (gmt 0)

5+ Year Member



This one looks like a winner, thank you!
 

Featured Threads

Hot Threads This Week

Hot Threads This Month