HP Surestore Disk Array 12h System Administrator's Guide for HP-UX, MPE, and W - Page 42

HP-UX Using the ARM Command Line Utilities for HP-UX Managing LUNs (Logical Drives) Managing LUNs (Logical Drives) An important part of managing the disk array involves defining and maintaining the optimal LUN structure for your system. Your system requirements and limitations will influence the LUN structure you choose. Managing LUNs is a part of the overall task of managing disk array capacity. For more information on managing disk array capacity to meet your system needs, refer to the HP SureStore E Disk Array 12H User's and Service Manual. Checking LUN Configuration When you are managing LUNs, you may find it convenient to check the current LUN configuration and the available capacity. To check the current LUN configuration and the available capacity, type: arraydsp -l [LUN] Creating a LUN Only capacity assigned to LUNs is visible to the operating system. When selecting the size for your LUNs, consider the following factors: • Any size limitations imposed by the operating system, for example, LVM. • Your backup strategy. If you do unattended backup to a device such as a tape, you may want to avoid creating a LUN that is larger than the capacity of the tape media. This allows you to back up an entire LUN without changing tapes. • Configuring the LUN into LVM for maximum performance as described in Table 2. NOTE! Before creating a LUN, check your operating system documentation for any additional information or steps that may be required to create a LUN. To create a LUN, type: arraycfg -L LUN -a capacity LUN must be an unused value between 0 and 7 Capacity must be less than or equal to the currently available unallocated capacity 42