From: Bill Verzal (Bill_Verzal@BCBSIL.COM)
Date: Mon Jul 22 2002 - 16:35:26 EDT
For one, the stripe size is kind of small. I usually stripe in sizes of
64K or bigger.
The Ultra-3 adapter is a 2-channel I believe. Are you connected to the
same channel as the disk (daisy-chained?) or are you on the other channel?
Even if you ran a separate cable, I think the drives connect to an internal
bus on the adapter, correct ? If so, are you on the same channel ?
Next time you run the restore, run "vmstat 3 10" and post the results.
Bill.
-----------------------------------------------------------------------------------------------------------
Bill Verzal
Technical Consultant
Forbes Technical Consulting
(312) 653-3684
bill_verzal@bcbsil.com
MailStop: 27.201C
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Sent by: IBM Subject: 2498 Ultra3 and 2104 RAID5 configure performance very very bad ???
AIX Discussion
List
<aix-l@Princet
on.EDU>
07/22/2002
02:46 PM
Please respond
to IBM AIX
Discussion
List
we have IBM P660 and AIX 4.3.3 O.S. on it. The P660 have 2498 Ultra SCSI3
RAID adapter card and connect seperate cables to 2104 disk array. We
configure 6 disks hardware RAID5 through "PDAM". while I load data from
LTO tape driver (high speed tape driver 15~30MB/sec) to this RAID5. the
performance is very very slow. Load 2Gb data toke 2hours to finish. I
use "topas" to check and found this RAID5 wrte speed is "550KByte/sec". I
called IBM support and support engineer told me nothing he can help.
Does anyone have expereince on it and can give me suggestion?
The configuration on 2498 RAID5 are:
6 disks raid 5
stripe size: 16K
command Queue Depth: 16
Thanks.
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