Optimising NFS for system files

[Bernard Dugas]

usleep wrote:
 > - Second installation
 >  - FreeNAS, RAID0
 >  - Tested throughput ( to local RAID0 ):
 >      - ftp: 82MB/s
 >      - nfs: 75MB/s
 >      - cifs/samba: 42MB/s

Thanks a lot for these clear references !

 > Test issues ( things that get you confused )
 >   - if you expect to be able to copy a file at Gigabit speeds, you
 > need to be able to write as fast to  your local disk as well. So to
 >  reliable test SAN/NAS performance at Gigabit speeds you need RAID at
 >  the server and at the client. Or write to /dev/null

This is what i did with the tar. What function do you use for testing ?

 >   - if you repeatedly test with the same file, it will get cached into
 > memory of the NAS. so you won't be testing troughput
 > disk->network->disk anymore: you are testing
 > NAS-memory->network->disk. I was testing with
 > ubuntu-iso's, but with 1GB of memory, ISO's get cached as well.

i was fearing that, but it seems that does not happen in my testing, as 
repeating same test give same result. I don't know why it does not 
happens...

 >  - if you repeatedly test with the same file, and you have enough
 > local memory, and you test with nfs or cifs/samba, the file will get
 >  cached locally as well. this results into transfer-speeds to
 > /dev/null exceeding 100MB/s ( Gigabit speeds ). i have observed
 > transfer speeds to /dev/null of 400MB/s!

I would love to see that behaviour. But it didn't happen neither in my 
testing :-(

 > We now have a NAS that performs faster than local disk.
      ^^^^
Is it the FreeNAS you describe in your testing or a new one ?

 >  We plan to use it run development-virtual-machines on.

This is also my target :-) I will have some high density servers (6 
independent servers in 1U) and trying to master the freebsd diskless 
process before...

Best regards,
-- 
Bernard DUGAS Mobile +33 615 333 770