NFS optimization

[David Gilbert]

>>>>> "Francisco" == Francisco Reyes <lists at stringsutils.com> writes:

Francisco> What would be a good way to determine how many nfsd
Francisco> proccesses one should have?  I erred in the side of caution
Francisco> since had to literally through an NFS setup into production
Francisco> without been able to do much testing. Set 35 processes.  My
Francisco> busiest nfsd are: 250 hours 50 " 24 " 11 " 7 " 4 " 3 " 2 "
Francisco> 1 "

Francisco> The rest are under 1 hour. Does that mean that I should be
Francisco> ok with 10 processes?

Roughly, yes.  You'll see NFSd's normally decline exponentially with
an inflection point.  If your machine is completely dedicated to NFS,
you probably want to run lots.  The overhead of extra NFSd processes
is fairly small.  If you rarely do NFS, the default of 4 may even be
overkill.

Consider that if you are "out" of nfsd's, the penalty is increased
latency for some small number of transactions that wait for an nfsd to
become available..  Even if you have tonnes of NFSd processes, if disk
is a limiting factor, more nfsd's won't speed the process.

Something that most peoople don't consider is that the number of NFSd
process can balance the concurrency of NFS clients against local disk
requirements.  If, say, you run a busy database on the NFS server, you
may want run fewer NFSd process to increase the disk bandwidth
resources available to the database.

Francisco> To kill the least active ones, I just "kill" them? or is
Francisco> there a better way to restart the whole nfs server side?

I rarely 'kill' an nfsd.  Always thought that was bad.  Killing any
nfsd is equivalent.  If you kill one that is further up the queue, the
ones later in the queue move up (AFAIK).  Still... I always change the
boot parameters and leave the processes currently running when I tune
the number of nfsd's.
  
>> trafshow will more quickly give you a handle on the traffic per
>> client.

Francisco> Thanks much. I see two versions in the port. Trafshow and
Francisco> trafshow3. Which one you recommedd?

I am currently running version 5.2.3 ... which is pretty fancy.  I
assume the port without the suffix installs version 5.  Both versions
will give you the required information, but trafshow 5 is much cooler.

Dave.

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|David Gilbert, Independent Contractor.       | Two things can be          |
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