Brian Mathis wrote:
> On Tue, Mar 8, 2011 at 12:24 PM, Michael Eager <eager@xxxxxxxxxx> wrote:
>> Hi --
>>
>> I'm running a server which is usually stable, but every
>> once in a while it hangs. The server is used as a file
>> store using NFS and to run VMware machines.
>>
>> I don't see anything in /var/log/messages or elsewhere
>> to indicate any problem or offer any clue why the system
>> was hung.
>>
>> Any suggestions where I might look for a clue?
>
> Please be more specific when you say it "hangs". Does it just pause
> for a minute and then continue working, or does it freeze completely
> until you reboot it? Does it respond to s "soft" reboot like
> Ctrl-Alt-Del, or do you need to hard power it off?
System is unresponsive. Monitor blank, no response to keyboard,
no response to remote ssh. Hit reset to reboot.
The only indication that I had that there was a problem (other
that attached systems were not accessing files) was that the fan(s)
on the server were louder than normal.
> Since this is an NFS server I'm going to guess there might be a lot of
> IO. Maybe there is some large IO load going on, like maybe all your
> VMs are running anti-virus scan at the same time, or something like
> that.
At the time, should be very low NFS load.
> To troubleshoot, I recommend installing the 'sar' utilities (yum
> install sysstat) and then reviewing the collected data using the
> 'ksar' utility (http://sourceforge.net/projects/ksar/). sar/ksar are
> good for tracking down acute problems.
Thanks for the suggestion. I'll look into sar.
--
Michael Eager eager@xxxxxxxxxxxx
1960 Park Blvd., Palo Alto, CA 94306 650-325-8077
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