Re: VIOS and Perf Monitoring

Not that all this isn't good discussion <grin>, but my original question was
basically how to measure disk performance at the VIOS level? If I didn't
use VIOS and hosted all my IBM i on top a IBM i partition I could use the
standard Performance Tools and things like WRKDSKSTS etc.



On Thu, Aug 25, 2011 at 5:06 AM, Jim Oberholtzer <midrangel@xxxxxxxxxx>wrote:

Rob,

You want to have a standard workload you can test with. At V7 use the
wait accounting tooling built in to the OS. A very good test is loading
PTFs from an image catalog. On smaller systems ( 4 or < drives) it is
often faster to load the CDs one by one than use the image catalog. All
I/O. I think it starts to even out at about 6 drives.

Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


On 8/25/2011 6:57 AM, rob@xxxxxxxxx wrote:

If I was to play around and unload/reload a lpar to test this, what would
be effective measuring?


Rob Berendt
-- Group Dekko Dept 1600 Mail to: 2505 Dekko Drive Garrett, IN 46738
Ship to: Dock 108 6928N 400E Kendallville, IN 46755
http://www.dekko.com From: Kirk Goins <kirkgoins@xxxxxxxxx> To:
Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx> Date:
08/24/2011 05:04 PM Subject: Re: VIOS and Perf Monitoring Sent by:
midrange-l-bounces@xxxxxxxxxxxx According to multiple IBM and NON-IBM
sources the answer is along these lines... The OS has no idea if these
disks are real or virtual. The OS will only queue so many I/Os per
disk arm available ( I think I got that right ). So if the OS only
sees one 280GB disk it will not handle I/O as well vs having eight
35GB disk arms. Now the actual number of real disks arms will affect
how well this concept works. On Wed, Aug 24, 2011 at 1:17 PM,
<rob@xxxxxxxxx> wrote:

I am still not getting why the OS needs to see multiple arms if they

are

all virtual. Instead of one bigger virtual. It's still physically

spread

across the multiple arms defined either in VIOS or your hosting

partition.

Is it some weird thing like "let's calculate your journal receiver

size

based on the number of arms you have"?


Rob Berendt
--
Group Dekko
Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com





From: Kirk Goins<kirkgoins@xxxxxxxxx>
To: Midrange-L<midrange-l@xxxxxxxxxxxx>
Date: 08/24/2011 04:12 PM
Subject: VIOS and Perf Monitoring
Sent by:midrange-l-bounces@xxxxxxxxxxxx



I am getting ready to build a system with VIOS as the Hosting OS and

will

be
running several IBM i partitions. I know I should use several

smaller

virtual disks vs 1 big one per partition so the IBM i OS wil see

multiple

disks/arms. So lets say I have 4 IBM i Partitions all on top of

VIOS.

Each
partition will see 8 35GB drives and lets say there are 24 139GB ( or
whatever size VIOS wants to call them ) drives available to VIOS to
allocate
disk space with. So lots of room but could use more arms. Now I

start a

really disk intensive process on 2 partitions. How can I tell how

busy

the

drives really are at the VIOS level? On a partition with IBM i

hosting I

can
do WRKDSKSTS on the base IBM i. Just wondering how to approach disk

perf

issues inthe future.

Thanks

--
Kirk
--

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