From: Olaf Kirch <okir@suse.de>
Subject: Re: knfsd brought to its knees, by a simple rsync or cp operation
Date: Mon, 28 Feb 2005 16:44:55 +0100
Message-ID: <20050228154455.GS4822@suse.de>
References: <20050226082854.2a496ec3@be.back.l8r.net> <20050228100633.GA4822@suse.de> <20050228102307.3788a184@be.back.l8r.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: nfs@lists.sourceforge.net
To: Brad Barnett <lists@L8R.net>
In-Reply-To: <20050228102307.3788a184@be.back.l8r.net>
Sender: nfs-admin@lists.sourceforge.net
Errors-To: nfs-admin@lists.sourceforge.net

On Mon, Feb 28, 2005 at 10:23:07AM -0500, Brad Barnett wrote:
> During my tests involving "ls", no one else was accessing the server.  I
> have noatime set for both client and server mounts.. just in case.
> 
> So, there should be no writes for knfsd to do.  There was only one
> read operation, and that was a "ls -R /nfsmount".

Well, you were talking about rsync and cp, so it's either reads or
writes going over the wire, or both.

> >  -	by tying up all knfsd threads on the server. Try to bump the
> >  	number of nfsd processes
> > 
> >  -	by tying up all RPC slots on the client. Make sure your wsize
> >  	isn't too big (8k is reasonable)
> 
> There is only one client (during my tests), so #1 can't be the case. 

One NFS client can issue many requests simultaenously, thereby tying
up more than one nfsd thread.

> This is what I don't understand.  Why is one single 'ls' on a single
> client, the only nfs client, brought to a standstill by a single cp or
> rsync?  It's very weird, and it does not seem to be because of write
> operations the client is performing.

Where do these cp and rsync calls occur? From your first message I
assumed they were on the client, operating on the NFS mounted file system.

Olaf
-- 
Olaf Kirch   |  --- o --- Nous sommes du soleil we love when we play
okir@suse.de |    / | \   sol.dhoop.naytheet.ah kin.ir.samse.qurax


-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now.
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs