Red Hat Knowledgebase

Please note that the parameter "acpi=noirq would be required in order to install the system with Update 3. At the boot prompt, the following would have to be provided:

boot: linux acpi=noirq

If an install is attempted without the above parameter, then the scsi bus resets are seen with the following messages repeated over and over:

 mptbase: Initiating ioc0 recovery
 mptscsi: ioc0: target reset: SUCCESS (sc=f754ec40)
 mptscsi: ioc0: attempting scsi bus reset! (sc=f754ec40)
 scsi0: destination target 5, lun 0
    command = Inquiry 00 00 00 24 00

'acpi=noirq' is needed on Red Hat Enterprise Linux 4 Update 3 because the Update 3 installer kernel operates in PIC mode. This causes the LSI driver on the HS21 to loop infinitely while waiting for the LSI chipset to initialize. Using 'acpi=noirq' works around this problem.

With Update 4, the installer kernel operates in APIC mode by default making 'acpi=noirq' unnecessary with Red Hat Enterprise Linux 4 Update 4.