Poor PE4600 NFS performance

Seth Mos knuffie at xs4all.nl
Tue Aug 6 01:57:01 CDT 2002

At 13:20 5-8-2002 -0600, Rick Gaudette wrote:
>We have recently received a PE4600 (PERC-3, RAID-5, RH-7.2) that is not
>performing nearly as good as we had hoped.  The primary function of this
>machine is an NFS server for a small gigabit network of athlon and P4
>workstations.  From the PE4600 we are seeing NFS read rates of ~14
>MB/sec.  Between all of the other machines we are seeing NFS read rates
>of 26 to 35 MB/sec.

Increase the following
#echo 262144 > /proc/sys/net/core/rmem_default
#echo 262144 > /proc/sys/net/core/rmem_max
And restart the NFS services. Newer kernels should do it automatically but 
try it anyways.
My 2.4.19 kernel automatically makes this 512K.

Use either the tg3 driver for the broadcom cards or the latest e1000 if you 
have it for the Intel EEPro 1000 gigabit cards. This is assuming that you 
are using copper GigE.

I get about 500Mbps NFS performance between poweredge servers so I think 
something is just wedged.
Mounts are done via fstab

coltex-2:/users/backup/lsautom  /mnt/backup     nfs 
rw,rsize=16384,wsize=16384,nfsvers=3,timeo=14,intr      0 0

The 16K seems to be the best trade off although 32K is more suitable to 
GigE which likes passing big network packets around.

>Are other folks out there able to get better performance out of this
>server?  Any help would be greatly appreciated.


It might just be your lucky day, if you only knew.

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