[K12OSN] SL 6.1 NFS client for FC 14, performance issues?

Roland Roberts roland at astrofoto.org
Mon Aug 29 04:39:31 UTC 2011


On 8/26/2011 6:10 PM, Roland Roberts wrote:
> On 08/26/2011 05:41 PM, Robert Arkiletian wrote:
[...]
>> also use no_subtree_check in /etc/exports
>
> I did add this earlier today and looked to see what cruft I might have 
> in my auto.home map. I keep bouncing the daemon on another exported 
> filesystem so I can test. be happy with factor of 2 difference between 
> local and nfs, but that factor of 6 is hurting.
>
> I'll try a few things and report back.

Well, I'm ready to throw in the towel. I'm not sure what the pattern of 
usage is that causes it, but...

I created a 4GB file from /dev/urandom on the NFS server. Then I mount 
the directory on the client can do a "time cat /mnt/junk.dat > 
/dev/null" on the client. Then I unmount the directory from both the 
client and server, remount on the server and repeat on another client.

If I do the "cat..." test directly on the NFS server, which is a Fedora 
14 32-bit machine, it takes 54 seconds. If I do it on a Fedora 14 64-bit 
client, it takes 70 seconds. If I do it on the SL 6.1 64-bit client, it 
takes 150 seconds. Multiple tries give results within a few seconds of 
those each time.

  NFS options are set the same:

[root at copernicus ~]# mount -v archos:/data/video /mnt
mount: no type was given - I'll assume nfs because of the colon
mount.nfs: trying text-based options 
'nfsvers=4,proto=tcp,noacl,ac,bg,nocto,lock,rsize=32768,wsize=32768,bsize=32768,mountproto=tcp,addr=192.168.3.3,clientaddr=192.168.3.36'
archos:/data/video on /mnt type nfs 
(rw,nfsvers=4,proto=tcp,noacl,ac,bg,nocto,lock,rsize=32768,wsize=32768,bsize=32768,mountproto=tcp)

The hardware between the two clients is not identical, but the LAN 
chipset is Realtek 8168B in all three cases but...the "bad" client has a 
rev 02 chip and the other two have a rev 01 chip. No idea if that 
matters, although I have found comments about the 8168B online that I'm 
not sure how to take. I do know that I can't enable a 4k MTU on these or 
NFS stalls *very* badly. As in I log in but hang trying to run my .bashrc.

I'm about ready to take the SL 6.1 motherboard and trash it. It's an MSI 
board, the only one I've ever had and I had some problems with it being 
very picky about what memory was in it, so I'm starting to wonder....

roland

-- 
Roland Roberts, PhD
http://www.astrofoto.org/




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