Subject: Re: nfs tuninng with raid
To: Brian Buhrow <firstname.lastname@example.org>
From: Greg Oster <email@example.com>
Date: 07/10/2001 13:15:57
Brian Buhrow writes:
> Hello folks. I've been trying to increase the performance of the
> box I'm using as a large RAID NFS server and have a few questions.
> I seem to be able to serve up about 160Kbytes/sec to about 8 clients
> simultaneously for reading, and about 50Kbytes/sec for writing. I've tried
> increasing the numver of nfsd's running, from 4 to 12, and the number of
> kern.nfs.iothreads from 1 to 12. This made things much worse. Knocking
> the number of iothreads down to 4, while leaving the number of nfsd's
> running make things better, but still not very fast, it seems.
> Running ps -lpid on the various nfsd processes shows that they're
> spending a lot of time waiting on vnlock or uvn_fp2. I tried increasing
> the number of kern.maxvnodes to 50,000 from 6,700, but this seems to have
> little to no effect.
> Any rules of thumb on how many iothreads
> for NFS are optimal, versus the number of nfsd's running? Are there rules
> of thumb on how to tune vnodes, and other parameters to help streamline the
> system? This is running in an I386 box with 1.5R kernel and 1.5 user land
> programs. The machine has a raid 5 array of 15 75GB IDE disks on it.
*15* drives? In a single RAID 5 set? What's the stripe width? (not that it
matters much with 15 drives). Also: what is the size of the files/data
being transfered in the benchmark, and/or what are you running as the
> It's using an Intel on-board 10/100MBPS ethernet adapter with the fxp
> driver in 100-MBPS/full duplex operation.
> Any suggestions/guides/things to look at would be greatly appreciated.