Subject: nfs tuninng with raid
To: None <>
From: Brian Buhrow <>
List: current-users
Date: 07/09/2001 22:20:07
	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.
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.