The selection of the logical drive from which the system is to be started is performed at IPL time. The user is presented with a panel containing a list of selectable logical drives. The user may explicitly select a logical drive, or may allow the selection timer to expire and have Boot Manager start the system from the default logical drive without further intervention.
If the time-out value was set to zero using the SETBOOT utility or FDISK/FDISKPM, the selection menu is circumvented and Boot Manager immediately starts the system from the default logical drive.
If the time-out value is other than zero, the selection menu is displayed as shown in Figure "Boot Manager Selection Menu".
If no default logical drive was specified, then the last system booted becomes the default.
The up/down cursor keys are used to select a particular logical drive. By default, the cursor is located at the current default logical drive. If more logical drives are configured in a workstation environment than lines are available on the screen to display them, a scroll bar will appear in the selection screen indicating to the user whether more logical drives are available for display.
The selection menu displays the current time-out value, and the boot name of the current default logical drive. In order to allow the user to suspend or resume the timer while the selection menu is displayed, the Esc key may be used in toggle mode. The current status of the timer is displayed (enabled/disabled) and the Esc key will toggle a status switch.
The selection menu shown in Figure "Boot Manager Selection Menu" is the standard mode normally seen at power-on or IPL time. Only the boot names of selectable logical drivers are displayed; no additional information about the type of logical drive and physical location is shown in order to keep the standard user interface simple and straightforward.
However, in order to accommodate advanced users and system administrators who wish to see more details about the available logical drives, an advanced mode menu is available. This advanced mode menu can be activated via an option in FDISK, FDISKPM or via the SETBOOT utility.
The advanced mode selection menu shows not only the boot names of the logical drives, but will also indicate the physical disk upon which the logical drive resides, the type of partition (primary/extended), the file system for which the logical drive was formatted, and the accessibility of the logical drive. The advanced mode selection menu is shown in Figure "Boot Manager Selection Menu - Advanced Mode".
Note that the third column displays the partition type for a logical drive boot name. Logical indicates that the drive resides in an extended partition.
The fifth column displays the accessibility of the logical drive. Hidden means the system will not have access to this volume; however, if a hidden boot name is selected as the logical drive from which to start the system, Boot Manager will "unhide" it. Boot Manager will automatically hide any other primaries on that physical drive, since only one primary partition may be active at any time.
Note: Only primary partitions can be marked as hidden, extended logical drives (partitions) are always accessible.