Compaq ProLiant 8000 Compaq ROM Technologies - Page 5

TC991204TB TECHNOLOGY BRIEF (cont.) ... REMOTE-FLASH REDUNDANT ROM Remote-flash Redundant ROM provides a disaster recovery mechanism for Compaq's missioncritical, high-end servers, such as Compaq ProLiant 8000 and ProLiant 8500 servers. Remoteflash Redundant ROM provides the capability to revert to a backup image of the System ROM firmware in the event that • The primary image becomes corrupted. • The original image is needed after an upgrade with the System ROMPaq. It is possible that new firmware from the System ROMPaq could have missing or bad code but not necessarily be corrupt. Say, for instance, the upgrade was missing code to support a new product feature required to make that product usable. In this case, a copy of the original image would be needed to restore the product's functionality. Remote-flash Redundant ROM provides automatic remote recovery of the last known good ROM image. Without this redundancy, the server would be unavailable after such an event until the administrator could restore the original ROM. Redundant ROM also allows administrators to load two good ROMs and select which of the two to use. Aside from providing a redundancy mechanism, Remote-flash Redundant ROM also improves system management by allowing ROMs to be flashed remotely. This can be achieved with the Compaq Remote ROM Flash Utility, discussed previously. The two technologies combine in Compaq's mission-critical servers to deliver a powerful solution that allows administrators to update ROMs for widely dispersed systems remotely and from a single point of execution, all while minimizing risk to availability. Redundant ROM Functionality For the initial configuration, the primary ROM image is stored on "A" ROM and the redundant image is stored on "B" ROM, as illustrated in Figure 2. As long as it is valid, the active image is always considered the primary image. A ROM Primary image (active) Revision ORG firmware B ROM Redundant image (inactive) Revision ORG firmware Figure 2: Initial ROM configuration. During boot time, the Boot Block ROM looks into the physical ROM to check the validity of the primary image. If the image is invalid, then an error code is generated, and the redundant image is marked primary and loaded instead (Figure 3). A ROM Inactive corrupted image Revision ORG firmware B ROM Primary image (active) Revision ORG firmware Figure 3: State of the primary and redundant images after detection of a corrupted primary image and system reboot. The operations for checking a valid ROM image and switching between the primary and redundant images are performed only during boot time. It is not possible to detect for a corrupted image at any other time. However, the error message should be automatically logged into the Compaq Insight Manager Error Log for error notification. 5