Chapter 4. CheckpointsCheckpoints display on the media subsystem operator panel and the virtual terminal while the system ispowering on and going through the initial program load (IPL). This chapter explains the IPL flow of thesystem and provides a table that lists checkpoints that you might see in the operator panel and in a virtualterminal window on the HMC.IPL FlowThe IPL process starts when ac power is connected to the system. The IPL process has the followingphases:v Phase 1: Service Processor InitializationPhase 1 starts when ac power is connected to the system and ends when OK is displayed in theoperator panel. 8xxx checkpoints are displayed during this phase. Several 9xxx codes may also bedisplayed. Service processor menus are available at the end of this phase by striking any key on theconsole keyboard.v Phase 2: Hardware Initialization by the Service ProcessorPhase 2 starts when system power-on is initiated by pressing the power on button on the operatorpanel. 9xxx checkpoints are displayed during this time. 91FF, the last checkpoint in this phase, indicatesthe transition to phase 3 is taking place.v Phase 3: System Firmware initializationAt phase 3, a system processor takes over control and continues initializing partition resources. Duringthis phase, checkpoints in the form Exxx are displayed. E105, the last checkpoint in this phase,indicates that control is being passed to the operating system boot program.v Phase 4: Operating System BootWhen the operating system starts to boot, checkpoints in the form 0xxx and 2xxx are displayed if thesystem is booting AIX. This phase ends when the operating system login prompt displays on theoperating system console.The following table outlines the IPL phases from power-on to the operating system login prompt, matchingthe phases to corresponding operator-panel checkpoints for a typical partition boot. Also listed are theapproximate boot times for each phase, along with their dependencies for each phase.Note: The following table lists the major checkpoints only.Phase # Checkpoints on OperatorPanel or HMCTime in Phase(minutes)Major Contributors to Time in PhasePhase 1 8xxx => OK Approx. 1Phase 2 9xxx => 91FF 3 to 6 Number of I/O drawersPhase 3 Exxx => E105 1 to 3 Number of bootable adaptersPhase 4 0xxx or 2xxx => blank (if bootingAIX)2 to 30+ Number of SSA drivesNumber of SCSI drivesNumber of async sessionsNumber of processorsNumber of adaptersAmount of memory131