Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!bcm!shell!nuchat!steve From: steve@nuchat.UUCP (Steve Nuchia) Newsgroups: comp.unix.wizards Subject: Re: System performance Keywords: sluggish, slow, non-existent Message-ID: <13436@nuchat.UUCP> Date: 11 Aug 89 14:40:34 GMT References: <932@lakesys.UUCP> Reply-To: steve@nuchat.UUCP (Steve Nuchia) Distribution: comp.unix.wizards,comp.unix.xenix Organization: Houston Public Access Lines: 15 In article <932@lakesys.UUCP> davef@lakesys.UUCP (Dave Fenske) writes: >When there is a disk intensive program running, if there is a lot of sequential >I-O, the performance level of SCO Xenix seems to drop to nill (NULL). This I have observed a similar phenomenon on my Bell Tech 386 3.0 system. In particular, I can run dd if=/dev/dsk/0s3 of=/dev/null bs=16k for instance and absolutely nothing else gets serviced on that disk until I kill it. I interpret this as an effect of the elevator algorithm. It would have to be modified with some kind of fairness provision to prevent this behaviour. -- Steve Nuchia South Coast Computing Services uunet!nuchat!steve POB 890952 Houston, Texas 77289 (713) 964 2462 Consultation & Systems, Support for PD Software.