Thanks for the answer Rick.
//Henrik
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT vm.marist DOT edu] On Behalf Of
Richard Rhodes
Sent: den 21 april 2010 20:40
To: ADSM-L AT vm.marist DOT edu
Subject: Re: [ADSM-L] disk question
I can tell you my understanding - right or wrong!
Operating systems keep lots of I/O queues . . at least these:
- a queue for each HBA.
- a queue for each LUN.
By spreading your db across multiple luns and hba's, you can get more
parallelism - assuming your application can make use of the parallelism.
This is why TSM also should have it's database defined using multiple volumes.
So you get multiple db vols across multiple lun's across multiple HBA's.
Will it help? It all depeneds . . .
The best thing I have ever read about this topic is the following. It doesn't
specifically address your question, but it goes into a deep dive about queuing.
http://virtualgeek.typepad.com/virtual_geek/2009/06/vmware-io-queues-micro-bursting-and-multipathing.html
Rick
Henrik Vahlstedt
<shwl AT STATOIL DOT COM
> To
Sent by: "ADSM: ADSM-L AT VM.MARIST DOT EDU
Dist Stor cc
Manager"
<[email protected] Subject
.EDU> disk question
04/21/2010 11:11
AM
Please respond to
"ADSM: Dist Stor
Manager"
<[email protected]
.EDU>
Hi,
Are there any performance benefits in creating two or more LUN´s in the same
RAID group for one RHEL 5, TSM 5.5 database, instead of only creating one LUN.
If yes, why?
Example: IBM Midrange System Storage Implementation and Best Practices Guide
sg246363, see chapter 7.4/TSM database.
//Henrik
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