Xen kernel doesn't find system root on aacraid provided disk

This document (7011923) is provided subject to the disclaimer at the end of this document.

Environment

SUSE Linux Enterprise Server 11 Service Pack 2

Situation

With SUSE Linux Enterprise Server 11 Service Pack 2, booting the
Xen kernel fails to find the system root device on aacraid provided
disk.

The boot log shows:

aacraid 0000:03:00.0: PCI->APIC IRQ transform: INT A -> IRQ 19
AACO: kernel driver panic'd: ffffffff
aacraid 0000:03:00.0: PCI INT A disabled

and the boot process ends with messages similar to:

Could not find /dev/disk/by-id/scsi-SServeRA_Drive_1_XXXXXXXX-part2.
Want me to fall back to /dev/disk/by-id/scsi-SServeRA_Drive_1_XXXXXXXX-part2?
(Y/n)

Where the device shown is an aacraid provided disk holding the root filesystem.

Resolution

A work around is to use the pci=nocrs boot parameter.

If this is occurring on certified hardware, please contact SUSE Support.

The hardware certification database can be found at https://www.suse.com/yessearch/

Cause

A bug in the BIOS is preventing the system from being able to properly
configure the aacraid adapter.

Using the pci=nocrs boot parameter avoids the issue by ignoring the PCI
host bridge window supplied by ACPI.

Disclaimer

This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.