HP Instant Capacity User's Guide for Version 9.x

7.3 Global Instant Capacity Group Managers
For each group, an HP-UX system must be designated as an active GiCAP Group Manager. This
system maintains information about the group, group resources, and grouping rules. Use the
icapmanage commands on a Group Manager system only.
The active Group Manager must be an HP-UX system running Instant Capacity software version
9.0 or later. The system running the Group Manager does not require any Instant Capacity
components, and it does not need to be a partitionable system. A Group Manager cannot be run
on a virtual machine (also known as a guest). The system must have a machine-readable serial
number, as displayed by the shell command getconf CS_MACHINE_SERIAL.
The Group Manager can be run on either a partitionable or a nonpartitionable system. If run on
a partitionable system, changing the configuration of the partitions can result in the Group
Manager becoming inoperative. For optimal availability, run the Group Manager on a server or
partition that is not a member of any GiCAP group, although it does not need to be dedicated
to only the Group Manager software. A Group Manager can manage multiple groups, but it is
recommended that it manages a single group for recoverability and ease of use.
7.3.1 Standby Group Managers
The active GiCAP Group Manager can designate a standby Group Manager to be available for
use as an active Group Manager if the current Group Manager is unavailable. The requirements
and recommendations defined for the Group Manager also apply to the standby Group Manager;
it is a Group Manager with “standby” status. This standby Group Manager is set up using the
icapmanage -a -S command on the active Group Manager system.
When the icapmanage -a -S command is issued, it sets up a cron job on the active Group
Manager that periodically transfers a copy of the GiCAP database to the standby Group Manager.
Prior to activating the standby Group Manager as the active Group Manager, the GiCAP database
on the standby Group Manager should match the database on the active Group Manager.
Although this is done automatically on a periodic basis, under some circumstances (such as
intermittent problems with network communication between the active Group Manager and the
standby Group Manger) the database on the standby Group Manager may be out of date. In this
case, you might need to manually transfer a copy of the database from the active Group Manager
to the standby Group Manager. This is done using the icapmanage -t command on the active
Group Manager.
The standby Group Manager can take control of GiCAP group management from the active
Group Manager using the command icapmanage -Q on the standby Group Manager. This
allows GiCAP group operations to continue if the GiCAP Group Manager is unable to function.
The new active Group Manager attempts to contact all group members, informing them that this
system is the active Group Manager. It also attempts to contact the previous Group Manager to
make it the standby Group Manager. The current system becomes the active Group Manager
regardless of whether or not these attempted contacts succeed or fail.
When the standby Group Manager becomes the active Group Manager, the cron job set up an
the former active (and now standby) Group Manager is removed, and a new cron job is set up
on the currently active Group Manager to continue the periodic transfer of a copy of the GiCAP
database to the standby Group Manager.
The standby Group Manager is removed using the icapmanage -r -S command on the active
Group Manager system. The active Group Manager updates all member hosts about the removal,
discontinues all GiCAP database transfer operations, and directs the standby Group Manager
to remove its copy of the GiCAP database.
The use of the icapmanage command is limited on a standby Group Manager. Only the -Q and
-s options are allowed, all other options are restricted to use only on the active Group Manager.
7.3 Global Instant Capacity Group Managers 103