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Conference ssdevo::hsz40_product

Title:	HSZ40 Product Conference

Moderator:	SSDEVO::EDMONDS

Created:	Mon Apr 11 1994
Last Modified:	Fri Jun 06 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	902
Total number of notes:	3319

818.0. " read sequentila on HSZ's performance " by EVTAI1::POUSSARD () Thu Mar 20 1997 11:22

	Hi,


	Could someone explain me why we can't go past 9 MB/s, when doing 
sequential read on a STRIPE or JBOD disk behind a HSZ20 connected to a 
KZPSA.


	It seems that HSZ family are powerful for random I/O like databases 
I/O, but not for sequential read or write. Am I right ???

	The best to do sequential read or write is to take 2 KZPSA and LSM 
striping

	Thanks for your answer


				Gilles.

T.R	Title	User	Personal Name	Date	Lines
818.1		SSDEVO::T_GONZALES		`Fri Mar 28 1997 19:53`	2
	You are correct, I think the problem is due to bottleneck at kzpsa, not the hsz.
818.2	more details?	NAMIX::jpt	FIS and Chips	`Thu Jun 05 1997 06:21`	6
	> You are correct, I think the problem is due to bottleneck at kzpsa, not > the hsz. Could you please explain what causes the KZPSA bottleneck as we've been able to get well over 16MB/s with KZPSA? I'd be interested in understanding what causes this kind of problem?
818.3		KERNEL::LOANE	Comfortably numb!!	`Thu Jun 05 1997 13:07`	3
	What's the I/O size?? In other words, could it be that the workload is throughput (rather than bandwidth) intensive?? ...and is the I/O spread over both HSZ20 ports?