From: John Jolet (john.jolet@FXFN.COM)
Date: Fri Jul 04 2003 - 13:16:22 EDT
we're doing something similar with a 6h1 and a fastt500. what we've done is set up 4 raid5 arrays, two hot spares in the frame. then we've carved up each array into various logical disks. We've got 12 disks in each array, so the db sees 4 hdisks, each of which is basically striped across 12 physical disks. Then you can set up other arrays for other things. We're seeing pretty close to gigabit performance (the 500 only has 1gig gbics), so the disk io is NOT the bottleneck. with the 700, i think you can have 2gig gbics in it, so your mileage might vary. If you only have 14 disks, I'd go raid5 for the db, then maybe 3 sets of two in a mirrored raid for the redo logs...remember, redo logs will be your highest io devices. what we will do is have 3 sets of redo logs, one on each array. then when we roll from, say redolog 1 to two, then redolog 1 starts writing to the archive log, the archive log writing and the redo log writing won't contend with the same disks. I'd say,!
depending on your database activity level, you might not have enough sheer spindles for optimum performance. Once you've set up your 4 arrays for the database, you can layer logical drives on them depending on your other needs, but you will have to watch performance as you go, to avoid contention. You also need to remember that the linux box by default won't scan past lun0...i'm working on that issue myself :)
The point is, the 700 will be plenty fast with raid5, don't waste disks on raid10 with this beast.
-----Original Message-----
From: dballester@KERNPHARMA.COM [mailto:dballester@KERNPHARMA.COM]
Sent: Friday, July 04, 2003 11:41 AM
To: aix-l@Princeton.EDU
Subject: What type of RAID to choose
Hi people:
I have a new p650 with FastT700. This FastT have 14 disks of 73 Gb.
We plan to give disk service to SAP/Oracle, Some linux servers ( samba ),
Lotus Notes, some type of document workflow, and some separate Oracle
machines. We are having some discussions on how to assign the disks to the
different servers. Once thinks that must be with only mirroring and
assigning separate disks to databases ( balancing data/index and giving
access on this disks only to database) The databases amount are less than
the disk amount. IMMO, i think that, in this case, may be more usefull
RAID10 of 12 Disks and 2 hot spare disks, creating Logical disks where is
amount should be part/multiple of real disk capacity. I know that all
servers will compete for disk access, but with RAID10, fastT cache, disk
speed and some stadistics, may be the wait for disk acces can be low...
Any tips? Anyone with this type of scenario?
Regards and TIAs, as always
David
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