nfs performance problem
Subsystems (2)
Quoted 8 lines · * Bernd Schubert ([email protected]) [071025 15:54]:
Hello Andreas,
Quoted 2 lines · On Thursday 25 October 2007 15:10:29 Andreas Schuldei wrote:
lotta:/var/disks/sda on
/var/disks/sdatype nfs (ro,hard,intr,proto=tcp,rsize=32k,addr=217.213.5.44) lotta:/var/disks/sdbtry to increase rsize and wsize as much as possible, the maximum can be adjusted in
/proc/fs/nfsd/max_block_sizeon the nfs server.
the with a max_block_size and rsize=512k i did not achive a noticable performance impact. increasing it to 2M decreased the performance to 12-12Mbytes/s per disk. do i need to adjust more tuneables to benefit from the increased size?
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i was suspecting that the nfs server reads the files in too small chunks and tried to help it with
for i in a h i ; do ( echo $((1024*6)) >
/sys/block/sd$i/queue/read_ahead_kb) ; doneAre your partitions on lvm or md? This wouldn't help then, AFAIK for lvm you can't do it via /sys, but must always use blockdev
they are on xfs directly on disk, no lvm or md involved.
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to get it to read in the files in one go.
I would hope to at least double the speed. do
you have a benchmark tool that can tell me the latency? i tried iozone and tried forcing it to only do read tests and did not get any helpfull error or output at all.First of all, what is you *local* performance?
i mentioned that i get 50Mbyte/s out of each disk, even when doing the dd on all four disks at the same time.
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