ALT IPL / Restart Device Versus Alternate Installation Device, D Mode Manual IPLs

Resolving The Problem

ALT IPL / Restart device, Alternate Installation device, D Manual mode IPLs.

Fibre attached tape drives can be used for Alternate IPL devices starting on POWER6 systems at R610 and only on IOPless adapters. Details about this enhancement are available at the following InfoCenter article: http://publib.boulder.ibm.com/infocenter/iseries/v6r1m0/topic/rzarm/rzarmwhatnew.htm?resultof=%22%

It is advised to install these IOP-less Tape Support PTFs: MF46933 and MF46687.

For Power5 systems and pre-R610, fibre-attached tape drives cannot be used as Alternate IPL devices (only as Alternate installation devices). Refer to Informational APAR II13199 for details on those systems.


Non-LPARed (Non-Partitioned) System

When a SLIC/LIC microcode CD is placed into the CD drive and the panel is set to D Manual mode, there is "boot strap" code already in the system to begin the power on and IPL of the system. This code then searches the system bus for devices at addresses 5,6,7 looking for an installation file. If no installation file is found, eventually the System Reference Code (SRC) B1xx 4609 is issued to the panel.

A common problem at this point is that the address of the tape drive is not set correctly (for example, address is still zeroes) or a CD/tape does not contain the installation file.

The operating system wants to see a device address of 5,6 or 7. However, when setting the SCSI address on the device, it should be 0,1 or 2.

Operating system device addresses are a binary inversion of SCSI device addresses as shown below:

SCSI Address			Operating System Device Address
Decimal	Binary		Decimal	Binary
0	000	< valid alternate IPL address >	7	111
1	001	< valid alternate IPL address >	6	110
2	010	< valid alternate IPL address >	5	101
3	011		4	100
4	100		3	011
5	101		2	010
6	110		1	001
7	111		0	000

Some tape drives cannot be addressed at 5,6,7 on the main system bus. Therefore, there is a method to IPL from one of the ALT IPL devices and then load enough code into the system to "walk" the buses and IOPs searching for these other devices ("Alternate Installation device"). This method uses the SLIC/LIC microcode CD to begin the IPL and then selects the MRI language feature (for example, 29xx, US English is 2924). On the next display, there are three DST options. Option 3 can then be used to find the other tape drive and select it to be used as the "Alternative Install" device. Returning to the DST display, Option 1 will continue the install IPL and the system will attempt to allocate and use the "Alternative Installation" device.

In addition, the D mode installation IPL uses only the microcode from the CD/tape installation file until a selection is made to restore (slip) or initialize (scratch) install the system. Once this selection is made, the SLIC/LIC microcode will begin to be loaded to the load source disk. When this completes, the system will change modes to A/B and begin a reIPL using the microcode just loaded on the load source disk.


LPARed (Partitioned) System

The primary partition will be D mode manually installed using the same method as a non-LPARed system.

The D mode of a secondary partition will be the most challenging part of the LPAR partition installation. This step will verify if the LPAR secondary partition is configured correctly and the minimum devices/IOPs (console, disks, tape/CD drive) required for the installation.

Because the partitioning support is logically performed and the primary partition is already installed and active, any CD/tape drive on any bus/IOP for the LPAR partition can be used as the ALT IPL device.

Verify the secondary partition's IOP settings of:
% - IOP which has the ALT IPL device
< - IOP which has the console
(Refer to Rochester Support Center knowledgebase document New, Determining Allocated and Tagged Resources for a Secondary Partition. To link to document New immediately, click here .)

If the D mode of the partition installation cannot find the tape/CD drive, there will be a series of 3 sets of SRCs in the history file of the secondary partition and end with a B2xx3110 SRC. The additional information of SRCs B2xx 3200 will provide the bus and address of the device attempted to be used for the ALT IPL. (Refer to Rochester Support Center knowledgebase document New, Displaying Secondary Partition Reference Code History. To link to document New immediately, click here .

A common problem is the tape/CD drive address was not correctly set or the installation file could not be found.

In addition, verify the configuration of the secondary partition to ensure that the values are set for the IOP of the tape/CD as the ALT IPL ( ). If you switch the device between partitions, that the ALT IPL maybe reset and must be set again prior to the D mode installation.

To circumvent the problem, if the CD drive can be found, perform a D mode IPL with a SLIC/LIC microcode CD and use the Alternative Installation method.

The D Mode Installation may receive resource allocation error if tape drive is being used as ALT IPL device and then selected as the Alternative Installation device.

If you already have the tape drive being used a the ALT IPL device during a D manual installation, do not use Option 3 to also select the tape drive as the Alternative Installation device.

Option 1 to continue the installation will fail with an resource unavailable allocation error because it is already being used as the ALT IPL device.

To correct the problem, use F12 to return back to the DST Install display and reselect Option 3 for Alternative Installation Device selection. Use Option 2 to deselect the bus/device. Then, Option 1 can be used to continue the D mode manual installation.