I'm having a quite strange issue. I'm mounting a NFS share from a SAN (ubuntu) to another machine (centos)

Mounting the share works just fine; but when I try some tests like :

dd if=/dev/zero of=bigfile bs=1k count=2000
2000+0 records in
2000+0 records out
2048000 bytes (2.0 MB) copied, 16.7555 seconds, 122 kB/s

On clientside, network has MTU 9000; i can successfully ping -s 8000 at least the server.

On SAN side it has 4 Gigabit interfaces bonded.

Both sides run NFS4; mounting using :

mount -t nfs4 /myshare/

Where should I start investigating ?

And what is the average transfer rate I could accept ? 50 Mb/s for a single gigabit connection ?

edit: server exports :

/export/share *(rw,insecure,async,no_subtree_check) 

edit: local storage test

time dd if=/dev/zero of=bigfile2 bs=1k count=200000
200000+0 records in
200000+0 records out
204800000 bytes (205 MB) copied, 0.509998 seconds, 402 MB/s

real    0m0.558s
user    0m0.009s
sys 0m0.546s
  • What if you repeat the test locally on the server? This way you can verify if it is NFS issue. What if you try larger file? What if you rsync/scp over SSH and test? What are your server export and client mount options? – grs May 13 '11 at 13:57
  • edited question with local test. I'll tryp scp and report. – Disco May 13 '11 at 14:04
  • ok scp gives an average of 52 mb/s; but it's with the encryption overhead i think, no ? should it be faster ? – Disco May 13 '11 at 14:06
  • Could you please show the client mount options? – grs May 13 '11 at 14:37
  • FWIW I've heard rumors NFS 3 is faster than 4... – rogerdpack Oct 8 '18 at 20:26

You could try using different mount options than the default. Might be worth trying the following using the mount -o option and reruning your dd test.

rw,bg,hard,nointr,rsize=32768, wsize=32768,tcp,timeo=600, actime=0

Try reading man nfs for details on the mount options and what they mean.

  • mount -t nfs4 -o rw,bg,hard,nointr,rsize=32768, wsize=32768,tcp,timeo=600,actime=0 doesn't seem to work. – Disco May 13 '11 at 14:04

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