Why is my load ave so high now? [Now I know why!]

[Kevin J. Cummings]

On 07/27/2009 02:26 PM, Rick Stevens wrote:
> You see a bunch of NFS-related things in a "D" state and you wonder why
> it's slow?

Yes.  Mostly because the machine accessing the NFS mounts has been
re-booted a couple of times.

> If you have processes in an I/O wait (a.k.a. "D") state, that'll bog
> stuff down badly...especially if the NFS mounts are mounted "hard".

Well, tonight I rebooted the server with NFS turned off.  When it
booted, I saw a load average between 1 and 2.  That's all.  When it
re-booted, ivtv started back up, despite my blacklisting it and removing
it from modprobe.conf.  However, ivtvfb did not get installed.
I also noticed that BOINC started right up again.  With astropulse
grabbing all the idle cpu time, my load average was still between 1 and 2.

So, I decided that NFS was my problem, but I'm still not sure why.

So, I tried a couple of things.  My laptop references a few directories
on my server via NFS and autofs.

So, I started nfs again on the server (service nfs start)

Load average remains between 1 and 2.  So far so good.

>From the laptop, I did a "cd /net/kjc386".  I can then do an ls and see
all of the exported filesystems.  Continues to look good.

"ls home" lists the directories in the server's exported /home dir.
nfs does the work, and disappears from the top -i that I have running.
Great.

Next I do a "ls c:" to look at the old WINDOWS partition on my server.
HANG!  I can't interrupt the ls with ^C nor ^Z.  I have to kill it from
another process.  When I do, the hung nfs processes on the server stay
hung.  After it collects all 8 allowed nfs processes, nothing more nfs
works to the server, and the load average climbs roughly 1 per nfs
process (I watched the load average increase with each new nfs process
that appeared).

So, I guess my question is what's broken with NFS between my F11 laptop
and the F10 server????

-- 
Kevin J. Cummings
kjchome at rcn.com
cummings at kjchome.homeip.net
cummings at kjc386.framingham.ma.us
Registered Linux User #1232 (http://counter.li.org)