User's Manual

As a result, there are different behaviors and constraints depending on whether any partitions
can be contacted on the specified member complex.
If, at the time of rights seizure, at least one member partition can be contacted, then the software
is able to make an immediate adjustment to the available core usage rights, just as if a normal
migration operation using icapmodify -d had been performed before the specified hard
partition stopped running. This makes core usage rights available for potential loans to other
member systems. In this situation, the seized core usage rights do not have an expiration date.
However, because other member partitions are running Instant Capacity software, you can
assume that the unreachable partition is using all cores on cells configured for that partition.
Unless an explicit restore operation is performed, when the failed partition is rebooted it will
have only the minimum number of core usage rights left after the rights seizure. Because of this,
cells in partitions from which usage rights have been acquired should be rebooted or made
inactive within 12 hours. If this is not done, the partition may begin to consume temporary
capacity. If temporary capacity is not available, the complex may no longer be in compliance
with the Instant Capacity contract. Cells may be made inactive by removing them from the
partition, shutting down the partition from within the OS by using shutdown -R -H, or with
the MP RR command.
If, at the time of rights seizure, all member partitions are unreachable, the rights seizure is deferred
and must be viewed as a limited and immediate loan of usage rights from the specified partition
to the group. This loan of seized usage rights expires in 10 days. Upon expiration, usage rights
are automatically restored to the member partitions from which they were seized. The expiration
date for a rights seizure operation effectively terminates the period during which the core usage
rights are available to other group members for purposes of disaster recovery. If none of the
member partitions are reachable by the expiration date for a particular member, the usage rights
are automatically restored (reassigned) to the member partition (or complex, in the case of
unassigned seized rights) from which they were seized. However, note that if the seized usage
rights have been redeployed to other members and are not released at the expiration time, the
group may go out of compliance or temporary capacity may be used to maintain compliance.
If any partition of the inaccessible member from which rights seizures were deferred reconnects
to the group before the expiration date, the seized core usage rights (for all partitions) are finalized
as a loan from the member to the group, the expiration date is no longer relevant, and the usage
rights can thereafter be manipulated with normal icapmodify operations.
The icapmanage -x operation can be performed once for each hard partition on the member.
Down Partitions with Powered-On Cells
Partitions that are not running an Instant Capacity daemon are assumed to be running another
OS and using all cores on cells configured in the partition. The Instant Capacity software can
avoid this assumption when all cells configured in the partition are powered down. Unless an
explicit restore operation is performed, when the failed partition is rebooted it will have only
the minimum number of core usage rights left after the rights seizure. Because of this, cells in
partitions from which usage rights have been seized should be rebooted or made inactive within
12 hours. If this is not done, the partition may begin to consume temporary capacity. If temporary
capacity is not available, the complex may no longer be in compliance with the Instant Capacity
contract. Cells can be made inactive by removing them from the partition, shutting down the
partition from within the OS by using shutdown -R -H, or with the MP RR command.
Temporary Capacity and Rights Seizure
Instant Capacity is designed to stop using temporary capacity and instead take advantage of
usage rights if any become available. If temporary capacity is in use during a failover sequence,
the activation on the failover node might need to specify the use of temporary capacity. After
the rights have been seized and before the activation on the failover node, there is a window of
time when the iCAP daemons (on other partitions in the group) can wake up and start using the
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