Linux, gobs of RAM, RAID and performance suckage...

[Paul Lussier]

Ric Werme <ewerme at comcast.net> writes:

> I have a lot of NFS experience, but not on Linux.  Please be real
> careful identifying what is client behaviour vs. server behaviour.
>
> The CPU load is on the server, and the client is nearly idle because
> the server is so slow to respond, right?
>
> You mentioned a load average > 40.  The first thing I'd do is run
> "ps" and see what processes are so busy.  Is the backup bogging down
> too or does that just keep rolling along?  If you suspend it, does
> NFS performance jump right back up?

Correct.  The nfsd's on the server get pushed to the bottom of the
queue (in top) and what I see is [kupdated] and tar (from the backups)
rotating between the top position.  There was one or two other
processes up there too, one of which I think was a kernel thread
([bdflush] ?).  As far a I know, the tar's were not making processes,
but I can't be totally sure of that.  Nothing *else* was making
progress, that's for sure.

> Data from /usr/sbin/*stat and /proc can be very interesting, I'm not sure
> what's the best for Linux.

It's looking more and more like this is going to be kernel tuning
excercise/learning experience :)

-- 
Seeya,
Paul
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