Reformatting IBM i pdisks to AIX hdisks

Edit: It has been a while since I have needed to do this.

Originally posted October 27, 2014 on AIXchange

Recently I needed to reformat an IBM i LPAR as an AIX LPAR for some testing. After defining the partition and reusing the IBM i hardware, I tried to boot it from physical install media (as there is no VIOS on this machine).

The OS would boot, but wouldn’t recognize any of the disks. If I went into maintenance mode and started a shell, lscfg displayed pdisks, but not hdisks.

This made sense, as these disks were still set up as an IBM i raid array. I needed to format them so that AIX could use them. The AIX boot media didn’t have the capability to format the disks; fortunately, IBM developerWorks had what I needed:

The IBM Standalone Diagnostics CD-ROM provides hardware diagnostics and service-related utilities for POWER, PowerPC, eServer i5 system with common pSeries I/O, and RS/6000-based systems. The standalone diagnostics CD-ROM would be used in the following situations when it makes sense to test the hardware independent of the operating system:

* When there is no operating system installed on a system or partition

* When the operating system does not have support for the service related function you wish to perform

* When there may be a problem with the boot device

* When the service documentation specifically recommends running standalone diagnostics

 The actual IBM Standalone Diagnostic CD-ROM can be downloaded here.

Diagnostics, which are available for AIX and Linux systems and logical partitions, can help you perform hardware analysis. If a problem is found, you will receive a service request number (SRN) or a service reference code (SRC) that can help pinpoint the problem and determine a corrective action. Additionally, there are various service aids in the diagnostics that can help you with service tasks on the system or logical partition.

You can run the IBM Standalone Diagnostic the following ways:

 * Running the eServer stand-alone diagnostics from CD-ROM
 
 * Running the eServer stand-alone diagnostics from a Network Installation Management server

I downloaded the standalone diagnostic CD and was able to burn the .iso image to physical media and boot from it. From there I went in and changed the pdisks to hdisks, formatting them as JBOD disks. Then I swapped CDs and put the install media back in the drive. AIX was able to recognize the disks, the OS was installed, and the test LPAR was easily built.