Re: knfsd brought to its knees, by a simple rsync or cp operation

[Olaf Kirch <okir@suse.de>]

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


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