Do check with your HA vendor. It used to be strongly recommended to have
this configuration (Data in ASP1 Receivers in ASP2+) It's not so much
any more even SAP recommends they all be together. Part of this is the
flat out number of arms. If you have say 12 arms and you end up with 8
in ASP1 and 4 in ASP2 even if you pull off the two RAID sets scenario
that's only 4 arms. Putting everything in ASP1 means 12 arms for
everyone in this example. The number of arms in the ASP with the Journal
Receivers also affects the size of the journal write buffers. More is
better up to something like 12 (memory fail?) disks in the ASP.
- Larry "DrFranken" Bolhuis
On 1/10/2014 10:54 AM, Bakutis, Becky wrote:
Thanks, with the new hardware I think this is the perfect opportunity to segregate the RAID sets so they don't cross ASPs.
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Kirk Goins
Sent: Friday, January 10, 2014 8:30 AM
To: Midrange Systems Technical Discussion
Subject: Re: Creating ASP for Journal Receivers
If you are journaling for DR, then putting the receivers in a different ASP that has a it own Raid Sets gives you the following ability.
If you loose the system ASP, you can restore the System ASP without loosing the data in say ASP2 where your receivers are. Apply last nights backups and then apply your journaled data.
If you loose say ASP2 and if it only contains journal receivers then that is all you have lost.
If say ASP2 shares a RAID Set with the System ASP and you looses that RAID set then you have lost BOTH ASPs
We used to put journal receivers in a different ASP for performance reasons. This moved the addition disk I/O of writing the journal entries to different disk. I have had IBM tell me with today's systems with much faster drivers, large cache controllers etc, many systems don't 'need' to put them in a separate ASP. Again that 2nd ASP needs to be on its own RAID set to isolate that I/O. Putting ASP2 on the same RAID set as the ASP1 really doesn't isolate the IO
On Thu, Jan 9, 2014 at 2:41 PM, Bakutis, Becky < BBakutis@xxxxxxxxxxxxxxxxxxxx> wrote:
We currently have a separate ASP for journal receivers on a busy system.
We will soon be upgrading the hardware. Someone mentioned, for DR
and performance reasons, to make sure no raid set crosses over into
another ASP when configuring the new hardware. Is this a valid
concern and worth the effort?
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