Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!brutus.cs.uiuc.edu!apple!rutgers!mcnc!rti!mcm
From: mcm@rti.UUCP (Mike Mitchell)
Newsgroups: comp.protocols.nfs
Subject: Nhfsstones
Keywords: nhfsstones, filesystems
Message-ID: <3392@rti.UUCP>
Date: 6 Jan 90 00:55:01 GMT
Distribution: comp
Organization: Research Triangle Institute, RTP, NC
Lines: 26

I've been playing with the 'nhfsstone' program from Legato Systems, Inc.,
and I've been wondering a few things.  As it comes from Legato, 'nhfsstone'
can only check out NFS file systems.  I looked at the code, and it reads a
kernel data structure to get statistics.  The statistics that is uses are
operation counts.  Each sub-process knows how many operations that it has
performed, but the parent process does not know how many operations each
child has performed.  Why can't the children communicate this information
to the parent using a temporary file or pipes?  Why is reading the kernel
data structure necessary?  (Because it is there?)

I modified the program to use shared memory to pass the data around, and
now I can get statistics for local file systems.  Does anyone see any problem
with this approach?  The only short comming that I see is that the program
does not know the actual load of the server, only the generated load.
The results of using this version would be skewed if the client and server
had a high load on them already.  The original 'nhfsstone' program checks
for a high client load.

I would like a way to compare other filesystems' performance to NFS performance
in a semi-standard way.  Does anyone have a better approach?

-- 
Mike Mitchell	{decvax,seismo,ihnp4,philabs}!mcnc!rti!mcm  mcm@rti.rti.org

"If you hear me talking on the wind, You've got
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