2 About Disk/Cache Partition
This chapter provides a detailed description of Storage Logical Partition (SLPR) and Cache Logical Partition (CLPR).
•Storage Logical Partition (SLPR), page 9
•Cache Logical Partition (CLPR), page 10
The storage systems can connect multiple hosts, and can be shared by multiple users, such as different departments or even different companies. This can cause conflicts among the various users. For example, if a particular host issues a lot of I/O requests, the I/O performance of other hosts may decrease. If the various administrators have different storage policies and procedures, or issue conflicting commands, that can cause management conflicts.
XP Disk/Cache Partition has two main functions: storage logical partition (SLPR), and Cache Logical Partition (CLPR). Storage Logical Partition allows you to divide the available storage among various users, to lessen conflicts over usage. Cache Logical Partition allows you to divide the cache into multiple virtual cache memories, to reduce cache contention.
Initially, SLPR 0 is the pool of all ports and CLPRs in the storage system. SLPR 0 contains CLPR 0, the initial pool of all cache and parity groups in the storage system. When another SLPR is created, the required resources are reassigned from SLPR 0 to the new SLPR. The only users who have access to SLPR 0 and CLPR 0 are storage administrators.
Storage Logical Partition (SLPR)
A storage system can be shared among several groups that may have different storage administrators. This can cause problems if those administrators have differing or conflicting storage procedures, or if two or more administrators attempt to perform operations on the same logical volume, such as LUN Expansion (LUSE) or Virtual LVI/LUN (VLL). The storage logical partition function can allocate the storage system resources into two or more virtual storage systems, each of which can be accessed only by the storage administrator, the storage partition administrator for that storage logical partition, and the users for that partition. You can create up to 32 storage logical partitions in one storage system, including the default SLPR 0. There is no maximum or minimum size for an SLPR. See “Creating a Storage Logical Partition” on page 29 for instructions on creating storage logical partitions.
Figure 1 illustrates a storage system that is divided into two virtual partitions, so that the storage administrator of each storage logical partition can only access that partition.
XP24000/XP20000 Disk/Cache Partition User's Guide | 9 |