Hi Sven, Can you show us the contents of /etc/exports on your head node?
I've had a similar problem in the past and managed to get better write speeds by adding 'async' to my exports options (have a look at `man exports`). Hope this helps! Regards, Andreas Roussos Systems Administrator Operating Systems Group University College London Sven Sternberger wrote:
Hello! I'm looking for a way to improve our nfs performance. We recently updated a small cluster (16 nodes). The nodes mount a share via nfs. I use nfs3 over tcp. I checked the disk write speed on the server (450mb/s) and the network thruput (980 mb/s). I tried udp, the deadline scheduler and large tcp buffers. SElinux and auditd is disabled, the server (Dell2950 w 8GB memory,PERC5) and my testnodes (Dell 1950 w 8 GB memory) both run 64bit SL5. What I see is >> always << ~20MB/s writing speed (reading is about 90mb which looks ok). I can see the 20MB/s also in iostat. Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util sdb 0.00 6511.63 0.00 83.39 0.00 25892.36 621.00 143.20 1552.83 11.96 99.70 My write test is: time dd if=/dev/zero of=./testme bs=1024k count=1000 I would expect that the write speed is higher. So any advice or explanation would be helpful best regards! sven
