Log files @ high load

postcd · 04-01-2014, 08:11 AM

Hi,

my VPS was overloaded and inaccessible for some time and i want to ask for help in which log files i need to look, or which tools to setup to monitor and find the cause of repeated hig load?

watched:
/var/log/messages
/var/log/secure
/var/log/httpd/access_log
/var/log/httpd/error_log
/var/log/mysqld.log
/var/log/lfd.log (config server firewall)
/var/log/fail2ban.log

but found no excessive entries, during overload, i cant access server so cant lookup the proceses i think

markseger · 04-01-2014, 02:36 PM

If you install collectl from sourceforge and start it up, it will record lots of system stats including process details including how much I/O each is doing. It will often (though certainly not always) help find the culprit. Could be a process is eating up your CPU or perhaps someone is beating up on the disks or networks. You never know until you grabs all the data in one place and look at it together.
-mark

nigelbarker · 04-02-2014, 01:43 AM

Sar can be a good tool too, though not always easy to set up.
In the past I've set the box to put a meaningful logfile into /var/www so I could look at it over a browser, this might help?

If you can't ssh to it, then something is really going wrong = can your hosting company give you any clues?

JuddRogers · 04-02-2014, 06:47 AM

Your hosting company has monitoring tools in place so they can bill you correctly. Those can at least tell you when the load was high. That might help figure out the problem.

Some offer collections of tools which you have to install to use but which can get you more data.