Datasheet

 cfgdev

 If you are using IVM, click Hardware Inventory and then click Configure devices to run

the cfgdev command.

After detecting the device, VIOS will automatically configure it and make it available for use. It

can then be virtualized to the IBM i client partition using the HMC, as described in the previous

section. Note that if the SAN configuration is performed before the VIOS partition boots, this step

is not necessary, as VIOS will recognize all available devices at boot time.

6 Attaching open storage to IBM i through VIOS:

Best Practices

6.1 Storage planning

The first storage planning consideration is to have sufficient available capacity in the open

storage subsystem to create the AIX/VIOS LUNs that will be virtualized to IBM i by VIOS. As

mentioned in the supported hardware the “IBM i using open storage supported configurations

section, it is strongly recommended that only FC or SAS physical drives are used to create

LUNs for IBM i as a client of VIOS. The reason is the performance and reliability requirements

of IBM i production workloads. For non-I/O-intensive workloads or near line storage, SATA or

FATA drives can also be used. This recommendation is not meant to preclude the use of SATA

or FATA drives for other clients of VIOS or other host servers; it applies only to production IBM i

workloads.

The storage subsystem may require a host kit for AIX/VIOS to be installed before attaching LUNs

to these hosts (as is the case with DS5000 or DS4000) for mapping the drives to IBM i using the

VSCSI adapters.

As the LUNs are virtualized by VIOS, they do not have to match IBM i integrated disk sizes. The

technical minimum for any disk unit in IBM i is 160 MB and the maximum is 2 TB, as measured in

VIOS. Actual LUN size is based on the capacity and performance requirements of each IBM i

virtual client partition and load source disk restrictions.

There is a limit of 64 unique LUNs (logical Units) per NPIV port prior to IBM i release 7.1 TR6.

With i 7.1 TR6 the limit is 128. 64 client partitions can share a single NPIV port. Since you have

only a 8 or 16 Gb physical port for the NPIV adapter you will have performance problems if too

many clients attempt to use the NPIV adapter at the same time. Note that with SVC/V7000 this

may include multiple paths to the same LUN. For that reason we say that you can have 128

unique LUN paths under a single client adapter. This same limit is applied to tape devices

configured via NPIV. Every control path tape drive has 2 LUNs, every non control path tape drive

has 1 LUN that apply to this calculation.

This LUN limit only applies to IBM i clients as the limitation is enforced by the IBM i licensed

internal code. The limitation of 64 partitions sharing a single FC port is enforced by the

HMC/VIOS, and so that applies to any type of client partition.

Direct attached or NPIV mapped LUNs for IBM i require an “IBM i host kit” on the storage

subsystem. On the Storewize V7000 IBM i uses the generic host support and does not require a

specific host kit.