NetNews Usenet Archive 1992 #26/NN_1992_26.iso/spool/comp/unix/ultrix/8201

Text File | 1992-11-09 | 1.6 KB | 33 lines

Newsgroups: comp.unix.ultrix
Path: sparky!uunet!usc!zaphod.mps.ohio-state.edu!caen!nigel.msen.com!yale.edu!ira.uka.de!Germany.EU.net!ifado!wb
From: [e-mail] (Wilhelm B. Kloke)
Subject: Re: Is local caching configurable?
Message-ID: <[e-mail]>
Organization: Institut f. Arbeitsphysiologie a.d. Uni Dortmund
References: <[e-mail]>
Date: Tue, 10 Nov 92 07:11:09 GMT
Lines: 22

In article <[e-mail]> [e-mail] (Kristina Buchholtz (9226)) writes:
>I'm using Ultrix 4.3, and have done some timing tests on
>local disk access vs. nfs disk access.  Nfs seems to be
>about twice as fast on writes of large files, and I am
This is quite normal, the data are cached three times when writing on NFS;
first normal Unix write cache; second the NFS server process and third
the write cache on the server.
>guessing this is because the data is cached.  Are there
>some parameters that can be tweaked to cause local data
>to be cached, to make local accesses as fast as nfs
They are always cached except when written synchronously.
>accesses?  (If so, would this be a bad idea?)  (I realize
>this nfs vs. local timing difference is not limited to
>Ultrix 4.3; I've found the same results on Ultrix 4.2 and
>SunOS.)
Of course you pay for the better write performance via NFS by loading
the server and using up it's memory. You may speed up your local write
access by adding more memory (bigger buffer pool) to your machine.
--
Dipl.-Math. Wilhelm Bernhard Kloke,
Institut fuer Arbeitsphysiologie an der Universitaet Dortmund
Ardeystrasse 67, D-4600 Dortmund 1, Tel. [phone]