Re: Disk RAID/mirroring/hot spares, etc

[Jim Oberholtzer <midrangel@xxxxxxxxxx>]

Chris:

The iASP is more a software issue than hardware, and it works best at 
V5R4 and up, but V5R3 will support it.  There are a number of objects 
that cannot reside in an iASP and that is where some of the complexity 
comes in.  Since it changes release to release, it's best to check the 
IBM web site for the specifics based on your OS level.  See: 
http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp?topic=/sqlp/rbafyiasp.htm
for V5R3 restrictions and you can find them easily from there right on 
up through V7.  The bigger the OS the better they get.

iASPs are directly tied to specific disk units (not raid sets) so you 
can have a 3 drive iASP that is part of a 10 drive raid set if you want 
to.  (I do it all the time, particularly for virtual tape)

iASP can in fact be mirrored with PowerHA software to a like iASP.  I 
don't believe you can currently mirror an iASP to a SAN at this time.

The biggest issue with iASP is it acts like a device on the system that 
can be varied on and off (start and stop it).  There are a couple of 
issues with recoverability in that you have to plan how to back them up 
and restore them, but that is not really a big deal once you get your 
head around the concepts.

They are a great tool and have lots of uses.  There are some limitations 
but the utility quickly overcomes the issues in my view.

Jim Oberholtzer
CEO/Chief Technical Architect
Agile Technology Architects, LLC


On 4/15/2010 1:28 PM, Chris Bipes wrote:
> *This message was transferred with a trial version of CommuniGate(r) Pro*
> I need to learn more about these iASP's.  What iSeries hardware level do
> you need to be at to create iASP's within your system?  What can be put
> onto an iASP?  What version of OS400, excuse me, i5OS is required to
> support iASP's?
>
> Can an iASP be mirrored to some remote SAN in near real time?
>
> Chris Bipes
> Director of Information Services
> CrossCheck, Inc.
>
> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx
> [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Jim Oberholtzer
> Sent: Thursday, April 15, 2010 11:06 AM
> To: Midrange Systems Technical Discussion
> Subject: Re: Disk RAID/mirroring/hot spares, etc
>
> Chris:
>
> By using iASP you would not have to create partitions.  You would of
> course need the mirror software (PowerHA or option 41) to do it.
>
>