Intel 7xx Servers, 170 Servers, AS/400 RISC Server 14.5 iV6R1M0 -- Vios and IVM Considerations

14.5 iV6R1M0 -- VIOS and IVM Considerations

Beginning in iV6R1M0, IBM i operating system will participate in a new virtualization strategy by becoming a client of the VIOS product. Customers will view the VIOS product two different ways:

yOn blade products, through the regular configuration tool IVM (which includes an easy to use interface to VIOS).

yOn traditional (non-blade) products, through a combination of HMC and the VIOS command line.

The blade products have a simpler interface which, on our testing, appear to be sufficient for the environments involved. On blades, customers are restricted to a single set of 16 logical units (which IBM i operating system perceives as if they were physical drives). This substantially reduces the number and value of tuning options. It is possible for blade-based customers to use the VIOS command line. However, we did not discover the need to do so and do not think most customers will need to either. The tuning available from IVM proved sufficient and should be preferred for its ease of use when it is workable.

Customers should strongly consider their disk requirements here and consult with their support teams before ordering. Customers with more sophisticated disk-based requirements (or, simply, larger numbers of disks) should choose systems that allow a greater number of LUNs and thereby enable more substantial tuning options provided from the VIOS command line. No hard and fast rules are possible here and we again emphasize that one consult with their support team on what will work for them. However, as a broad rule of thumb, customers with 200 or more physical drives very likely need something beyond the 16 LUNs provided by the IVM environment. Customers below 100 physical disks can, in most cases, get by with IVM. Customers with 50 or fewer very likely will do just fine with IVM.

IBM i 6.1 Performance Capabilities Reference - January/April/October 2008
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