Assigning a Cell to a Partition

A cell can be assigned to a partition only if there are sufficient cell usage rights available across the complex, as well as sufficient memory usage rights to enable activation of all the memory on the cell, and sufficient usage rights for at least one core of the cell to be active.

When a cell is assigned to a partition in an Instant Capacity system, depending on the number of core usage rights available in the system when the cell is assigned, the number of intended active cores for the partition automatically changes. The following example of a single partition with one assigned and one unassigned cell illustrates this:

Figure 4-2 Partition pre-modification state: One cell assigned with 3 active and 1 inactive cores, and available usage rights for 2 additional cores

Figure 4-3 Pre-modification state: Unassigned cell with 4 inactive cores without usage rights

Figure 4-4 Partition post-modification state: Cell 2 assigned to partition

When Cell 2 is assigned to the partition, the number of intended active cores for the partition is automatically changed to 5. When the partition is rebooted, 5 cores in the partition are activated.

When an unassigned cell is assigned to a partition via the parmodify command, the Instant Capacity software determines the number of available core usage rights in the complex and will use this number to activate as many cores as possible in the new cell. (This number will typically correspond to the icapstatus value for Additional cores that can be activated with current usage rights or the actual number of cores, whichever is smaller. This value must be nonzero in order to be able to assign an inactive cell to a partition.)

However, when a new partition is created via the parcreate command, core usage rights must be available for all cores configured on the new partition's cells, and core usage rights will automatically be assigned to these new cells. See also “New Partition Creation and Instant Capacity”.

Note that when determining available usage rights, the Instant Capacity software calculates the usage rights consumed by each partition to be the greater of either the Actual Active or Intended Active cores for the partition.

	NOTE: Cell boards are assigned to specific partitions and cannot be shared between partitions. All cores on a cell board are accessible only by the partition to which the cell board is assigned. Cores on one cell board cannot be shared across multiple partitions.