HP Surestore Disk Array FC60 HP SureStore E Disk Array FC60 - (English) Advanc - Page 242

Managing Disk Array Capacity During installation, a LUN structure is created on the disk array. This structure may meet your initial storage requirements, but at some point additional capacity may be required. This involves adding disks and binding new LUNs. Careful LUN planning will ensure that you achieve the desired levels of data protection and performance from your disk array. Altering the characteristics of an existing LUN such as its size and RAID level requires unbinding and rebinding the LUN - a time consuming process. With careful planning you can avoid having to reconfigure the disk array when adding disk array capacity. Configuring LUNs The primary task in managing disk array capacity is creating the LUN structure you need. Factors such as capacity, RAID level, and stripe segment size must be determined for each LUN. The LUN configuration you select should be based on system environment and application needs. The process of binding LUNs is much like adding new disks to your system. Each LUN appears to the host as a single hard disk drive. However, unlike conventional hard disks, the disk array gives you the flexibility to control the size and operating characteristics of each LUN . When binding LUNs, consider the following: • Any size limitations imposed by HP-UX or LVM. • The maximum numbers of LUNs that can be created on the disk array is 32. Because LUN numbering begins at 0, the highest LUN number is 31. • Your backup strategy. If you do unattended backup to a device such as tape, you may want to avoid creating a LUN that is larger than the capacity of the media. This allows you to backup an entire LUN without changing media. 242 Managing Disk Array Capacity