HP rp7405 HP-UX 11i v3 Dynamic nPartitions - Features and Configuration Recomm - Page 6

Figure 1 illustrates a configuration appropriate for this scenario. Suppose a server complex consisting of eight cells were partitioned with cells 0 and 1 as base cells in partition 0; cells 2 and 3 as base cells in partition 1; and cells 4 and 5 as base cells in partition 2. Cells 6 and 7 are floating cells that can be assigned to the partition that needs them most at the time. Figure 1. Application 0 Application 1 Application 2 nPartition 0 nPartition 1 nPartition 2 cell 0 cell 1 cell 2 cell 3 cell 4 cell 5 cell 6 cell 7 base cell base cell base cell base cell base cell base cell f loat cell f loat cell If the applications running on partition 0 experienced peak load when partitions 1 and 2 were relatively underutilized, cell online addition operations are used to add cells 6 and 7 to partition 0. If the workload pattern changed so that partition 2 needed more capacity, cell 6 is online deleted from partition 0 and then online added to partition 2. The two floating cells continue to be migrated among the partitions to follow the workload peaks. A variation suggested by a customer is to place tape drives or other shared specialized peripherals on one of the floating cells. This floating cell could be migrated into the various partitions as need dictates. This would allow tape backups to be accomplished at local transfer speeds rather than network transfer speeds. Temporary removal of a partition Floating cells can be created by temporarily removing one or more partitions. For example, a server complex could be divided into a production partition and a development and test partition. During times of urgent production need, such as a retailer satisfying a holiday peak, you can shut down the development and test partition and use its cells as floating cells to be online added to the production partition. When the production peak has abated, the floating cells can be online deleted to reconstitute the development and test partition. Replacement of hardware In the preceding scenarios, cells migrated from one partition to another while remaining within the cellular complex. When a cell is online deleted from a partition, it can then be powered down and physically removed from its cabinet. This would allow components on the cell board or the entire cell board to be replaced. The replacement capability enables hardware maintenance to be performed, for example, if predictive diagnostics indicated that a certain memory DIMM or processor module was likely to fail and should be replaced. It is possible to increase the number of DIMMs in a cell board or replace DIMMs with denser components. 6