Q: I have several older Itanium machines such as the rx6600 that are failing to reboot automatically. I have to run the EFI shell. Then manually run reconnect –r and map –r to find the boot paths.
A: This has been a very annoying (and sometimes intermittent) problem for several years. Since rebooting HP-UX does not normally happen a lot, the problem is just worked around then forgotten. The reason is actually in the SAN switch.
Most SAN switches (HP, Cisco, Brocade, McData) can perform auto speed negotiation, similar to Ethernet speed sensing. However, older fibre interface cards (HBAs) such as Tachyon will enter an idle state when reset. This occurs when the system is rebooted or reset with tools like fcmsutil. In this idle state, the light is unmodulated (no data) and will trigger speed negotiation to start in the SAN switch. Since the card stays in the reset state for a long time during a reboot, speed negotiation fails multiple times and causes the port to become disabled for a 2 minute period (for Brocade models).
As the system begins to reboot, the EFI code will scan to locate bootable paths. Unlike PARISC, the EFI code must identify bootable paths – there is no way to specify a known-to-work path. The EFI code enables the fibre cards but the port(s) are still disabled at the switch and thus, no SAN-based boot paths are seen. At this point, the system administrator must start the EFI shell to run reconnect –r followed by map –r. If the 2 minute disable period expires, speed negotiation has been completed and the mapping for bootable devices succeeds. If the boot to the EFI shell is fairly rapid (less than 2 minutes), then the reconnect/map sequence will still fail and must be repeated to succeed.
The fix is to disable auto-negotiation and lock the SAN port to the highest speed available for the Itanium HBAs. This will prevent the switch from disabling the port(s) during reboot.
– See more at: http://serviceitdirect.com/blog/itanium-boot-san-fails#sthash.QTH959za.dpuf
Tags: Itanium