NFS over TCP performance

[Felix Radensky <felix@allot.com>]

Hi,

I'm testing NFS server performance in the following environment:

NFS server :
 
Compaq Proliant ML 350,
dual 1.33 GHz CPU,
1G of RAM,
132G RAID5 based on Compaq Smart Array 532 (cciss driver),
linux-2.4.19-pre10 SMP kernel with latest NFS_ALL and NFS TCP patches,
ext3 filesystem with internal 400M journal,
NFS version 3,
nfs-utils 0.3.3,
e100 NIC driver version 2.0.30,
16 nfs server threads,
rmem_default and rmem_max are set to 1048576
 
NFS client:

Dual 1G CPU board based on ServerWorks chipset,
1G of RAM,
linux-2.4.18,
NFS version 3,
mount-2.11b,
e100 NIC driver version 2.0.30

Client and server are connected to 10/100 Cisco switch,
which is not congested, and both are synchronized to
100 Base Tx Full Duplex.

Client mounts /users directory like this:

mount -o rsize=8192,wsize=8192,hard,intr,tcp server_ip:/users /users

My test, as explained in Linux NFS howto, consists of copying a 2G
file, from client to server, like this

time dd if=/dev/zero of=testfile bs=8k count=262144

It takes about 4.5 min to complete the write. The same test, but over UDP,
takes around 3 min. My question is: is NFS over TCP supposed to be much
slower than over UDP, and if no, how can I improve the performance.
I've tried other values for rsize/wsize, but 8k seems to give the best 
performance.
I've also tried mounting ext3 filesystem with data=journal, but then 
test runs
about 4 times longer.

TIA,

Felix.


_______________________________________________________________

Sponsored by:
ThinkGeek at http://www.ThinkGeek.com/
_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs