*BSD News Article 81444


Return to BSD News archive

Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.mira.net.au!news.netspace.net.au!news.mel.connect.com.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!newsfeed.internetmci.com!solaris.cc.vt.edu!deepthot!brtph500.bnr.ca!nrtphba6.bnr.ca!bcarh189.bnr.ca!bcarh8ac.bnr.ca!bmdhh222.bnr.ca!chriseb
From: chriseb@nortel.ca (Chris (C.) Ebenezer)
Newsgroups: comp.os.linux.development.system,comp.unix.bsd.freebsd.misc
Subject: Re: Linux vs FreeBSD disk io performance
Followup-To: comp.os.linux.development.system,comp.unix.bsd.freebsd.misc
Date: 24 Oct 1996 11:45:54 GMT
Organization: Bell Northern Research
Lines: 30
Message-ID: <54nkti$oh9@bmdhh222.bnr.ca>
References: <86g23ey1uc.fsf@romulus.ihosteng.priv.no> <545di1$tvd@halon.vggas.com> <32667BBA.12A8@indy.celebration.net>
NNTP-Posting-Host: bmdhh164.bnr.ca
X-Newsreader: TIN [version 1.2 PL2]
Xref: euryale.cc.adfa.oz.au comp.os.linux.development.system:34018 comp.unix.bsd.freebsd.misc:29861

John S. Dyson (dyson@indy.celebration.net) wrote:
: James Youngman wrote:
: > 
: > In article <86g23ey1uc.fsf@romulus.ihosteng.priv.no>,
: > ivarh@romulus.ihosteng.priv.no says...
: > >
: > >To see this you who have both operating systems installed can start
: > >the command: dd if=/dev/<root partition> of=/dev/null bs=409600&
: > >4 times a minute apart. After doing this try the df command or a ls -l
: > >on both systems. On the FreeBSD system I barly notice that something
: > >is going on. The linux systems feals realy clumsy. This is on the same
: > >machine.
: > >
: > >Can someone explain this different behaviour?
: > 
: > Under linux, df does a sync().
: > 
: Try GNU df or ls under FreeBSD to see if there is a difference.
: FreeBSD does not accumulate nearly as many dirty blocks as
: Linux, and so will probably behave better even using the
: GNU tools.

And besides the sync() call with Linux doesn't actually write the disk blocks
as has been pointed out earlier, so basically theer are other factors involved
here that cause the delay with Linux's df.

Chris

--