AP Boot Sequence

This subsection briefly describes the flow of events that occur when the Sun Enterprise 10000 server is booted on an alternately pathed boot disk. This sequence of events illustrates how auto switching of the boot disk controller is achieved during the boot process, if such a switch is necessary. The boot sequence proceeds as follows:

1. By default, the system is booted from the device specified by the OBP devalias boot-device. Note that this device may be different from the last active alternate for the boot disk.

2. OBP stores the path to the boot disk on the SSP.

3. If a failure occurs, it is detected after about one minute. Then, the AP Reboot Host program is executed.

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   Note -

   One or two minutes may pass before action is taken, so do not immediately enter new commands if you notice that the boot process has failed. If you attempt a manual recovery from a boot failure, be aware that the automatic reboot recovery process will still be executing and may override your manual recovery command.

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4. AP Reboot Host retrieves the path stored earlier by OBP, and communicates the path to the AP SSP daemon.

5. The AP SSP daemon looks up the alternate path for the boot disk in the AP SSP database, and retries the boot process with the other alternate path.

6. After the reboot succeeds, AP determines the alternate from which the system was booted, and makes it the active alternate.