System performance

Steve Nuchia steve at nuchat.UUCP
Sat Aug 12 00:40:34 AEST 1989


In article <932 at lakesys.UUCP> davef at 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.



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