Need Help Diagnosing Server Wierdness

[Matt Graham]

From: Mark Phillips 
> I have an old headless server running Linux kernel 2.6.32, Debian
> Squeeze. Recently, when I log in using ssh the terminal window freezes
> for a few seconds, then usually comes back. The command line stops
> printing the characters I am typing, the cursor stops blinking, and
> then after a few seconds, it comes back. This happens every few
> minutes

> # df -h
> /dev/sda1             182G   42G  131G  25% /
> /dev/sdb1             230G  146G   72G  67% /mnt/sdb
> 
> How should I go about diagnosing this problem?

If it keeps happening on a semi-regular schedule, and the server's old/slow,
it may due to disk I/O.  Have a look in dmesg for anything relating to
read/write errors on a disk.

Or it's a process that's regularly showing up, doing something that blocks
everything (not sure what), and then going away again.  You could try to
capture this by doing "top -b -n 50 > toplog.txt", which will run top in batch
mode 50 times (~100 seconds wallclock), so you can then have a look at the
file later and look at which processes are running when the machine freezes.

-- 
Matt G / Dances With Crows
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