14.5.1.3 VIOS and JS12 Express and JS22 Express Considerations
Most of our work consisted of measurements with the JS22 offering and external disks using the
DS4800 product. The following are results obtained in various measurements and then a few
general comments about configuration will follow.
14.5.1.3.1 BladeCenter H JS22 Express
running IBM i operating system/VIOS
The following tests were run using a 4 processor JS22 Express in a BladeCenter H chassis, 32
GB of memory and a DS4800 with a total of 90 DDMs, (8 DDMs using RAID1 externalized in
2 LUNs for the system ASP, 6 DDMs in each of 12 RAID1 LUNs (a total of 72 DDMs) in the
database ASP, and 10 DDMs unprotected externalized in 2 LUNs for the journal ASP). We had
two Fibre Channel attachments to the DS4800 with half of the LUNs in each of the ASP’s using
controller A as the preferred path and the other half of the LUNs using controller B as the
preferred path. The following charts show some of the performance characteristics we observed
running our Commercial Performance Workload in our test environment. Your results may vary
based on the characteristics of your workload. A description of the Commercial Performance
Workload can be found in appendix A of the Performance Capabilities Reference.
Creating and running multiple LPARs can lead to unique system management challenges.
Reference. The following is a link to an LPAR white paper.
http://www.ibm.com/systems/i/solutions/perfmgmt/pdf/lparperf.pdf.
.
For most of our testing we only utilized one IBM i operating system partition on our JS22
Express. Note that VIOS is the base operating system on the JS22 Express, installed on the
internal SAS Disk and VIOS must virtualize the DS4800 LUNs and communication resources to
the IBM i operating system partition, which resides on the DS4800 DDMs.
VIOS/IVM must have some of the memory and processor resources for this vrtulization. The
amount of resources needed will be dependent on the physical hardware in the Blade Center and
the number of partitions being supported on a particular Blade. For our testing we found that we
could not operate with under 1 GB of memory and for all of the tests in this section we used 2
GB of memory. The number of processors varied for each experiment and the charts will define
the processors used in that experiment.
One important thing to note is that we only changed the amount of memory and processors in the
VIOS partition. Otherwise the rest of the settings for the VIOS partition are as they default when
the basic configurations is created during the VIOS install. So the VIOS partition processors in
my experiments are always set up as shared, only the IBM i operating system partition is created
using dedicated processors.
IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
©
Copyright IBM Corp. 2008
Chapter 14 DASD Performance
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