tuning hints for PAE

Scott Long scottl at freebsd.org
Thu Jul 15 12:01:47 PDT 2004


Daniel Lang wrote:

> Hi Scott,
> 
> Scott Long wrote on Thu, Jul 15, 2004 at 12:38:29PM -0600:
> [..]
> 
>>Look at kern.maxvnodes and trim is down to a smaller amount if it's more
>>than about 100,000.  This of course depends on your workload.  If you
>>really need a lot of cached vnodes, then you'll need to tune elsewhere.
> 
> [..]
> 
> I was set to some value > 200000. I trimmed it down to 64000.
> Caches vnodes help if I access many different files concurrently?
> 
> The machine hosts a heavy loaded ftp server, but I guess 200000
> is a very very high value. Is there some way to check the 
> vnode cache utilization? Maybe with vmstat -m ....
> 
> Thanks,
>  Daniel

bash$ sysctl -a |grep vnode

kern.maxvnodes: 17806
        vnodes    21     5K      5K      145  16,32,64,128,256
kern.minvnodes: 4451
vm.stats.vm.v_vnodein: 3930
vm.stats.vm.v_vnodeout: 0
vm.stats.vm.v_vnodepgsin: 25583
vm.stats.vm.v_vnodepgsout: 0
vfs.numvnodes: 16133
vfs.wantfreevnodes: 25
vfs.freevnodes: 8096
debug.sizeof.vnode: 260

The indented line is from kern.malloc and gives you an
estimate of how much memory is being consumed by the
vnode pool.

Scott


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