Interface Card Critical Resource Analysis(CRA) Whitepaper for HP-UX 11i v3

Criticality reported by CRA:

CRA_DATA_CRITICAL

Explanation and user action required:

The olrad(1M) command with –C option reports the resource usage and its criticality.

The above operations with scsimgr and the olrad(1M) with –r or –d options will fail with

CRA_DATA_CRITICAL error.

If any of these operations must be performed for system administration purposes, the user must ensure

that the alternate boot disk is reachable through an alternative path (in case of the scsimgr operation)

or an alternative healthy card (in case of the olrad operation) before performing the above

operations.

However, the user may override this error using the olrad –f option and the scsimgr disable –F option.

However, overriding the error and proceeding with the above operation, without making an

alternative lunpath available, will leave the system without any alternate boot path set.

Scenario 4

System Configuration:

HP-UX OS running from a boot disk with one or more lunpath(s) through I/O

cards controlled by the same driver.

Operation Performed:

# kcmodule <interface driver associated with card>=unused

Criticality reported by CRA:

CRA_SYSTEM_CRITICAL

Explanation and user action required:

The above operation with kcmodule will render the boot lunpath unavailable and this will result in

system crash, hang, or any other indeterminate system state.

Because of the above reasons, the requested operation will not be allowed by CRA to proceed and

the operation will fail with CRA_SYSTEM_CRITICAL error.

If this operation must be performed for system administration purposes, then, before performing the

operation, the user must configure another lunpath to the boot disk through a different I/O card

driver, than the one that is going to be currently unloaded.

NOTE: If the boot disk had a single lunpath and a kcmodule operation is attempted, as mentioned

above, though the kcmodule operation fails with CRA_SYSTEM_CRITICAL, it still marks the interface

driver as unused for the next boot. That is, the corresponding interface card driver is removed from

the kernel configuration that is marked to be used during the next boot of the system. Therefore, when

the system is rebooted, the system will panic on the next boot since it can not find the interface card

driver for boot path.

In such a scenario, to avoid the panic due to the interface card driver for the boot path not being

configured, before rebooting the system, the user can run one of the following commands:

• Discard all kernel configuration changes marked for the next boot of the system, by

running:

# kconfig –H

To verify that all the kernel configuration changes have been discarded, run:

# kconfig –D