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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!spool.mu.edu!newspump.sol.net!ddsw1!news.mcs.net!www.nntp.primenet.com!nntp.primenet.com!howland.erols.net!EU.net!Norway.EU.net!guardian.merkantildata.com!romulus!usenet From: Ivar Hosteng <ivarh@romulus.ihosteng.priv.no> Newsgroups: comp.os.linux.development.system,comp.unix.bsd.freebsd.misc Subject: Linux vs FreeBSD disk io performance Date: 16 Oct 1996 22:35:23 +0000 Organization: None Lines: 31 Message-ID: <86g23ey1uc.fsf@romulus.ihosteng.priv.no> NNTP-Posting-Host: romulus.ihosteng.priv.no X-Newsreader: Gnus v5.3/Emacs 19.34 Xref: euryale.cc.adfa.oz.au comp.os.linux.development.system:33578 comp.unix.bsd.freebsd.misc:29373 I have been using Linux for 1 1/2 years now. I am using my system as a news server and a mailserver for a small network. When the news is beeing expired I can notice a clearly drop in disk performance. The df command takes about 2-6 seconds to complete and logging in also has sevral delays caused by the disk IO the expire process creates. My system is a 96MB 200Mhz PPro system with a 4MB SCSI II barracuda disk connected to a Adaptec2940 SCSI controller. The last weekend I tried to install FreeBSD 2.1.5 and have transfered the news to the new partition. Here there is no delay in the system when it is expiring news. Other tests I have done seems to comfirm that FreeBSD is handling heavy disk IO with more grace than linux (2.0.21) does. This message is not meant as flaimbait but as a question of what it is that makes Linux behave so clumsy when I performe heavu disk IO. 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? -- Cheers, Ivar Hosteng email: ivarh@ihosteng.priv.no finger ivarh@ihosteng.priv.no for my PGP key