HP XP P9500 Storage - Manual (Page 44)

3 Configuring custom-sized provisioning
Configuring custom-sized provisioning involves creating and configuring a customized volume
(CV). A CV is a fixed-sized volume that is divided into arbitrary sizes.
This provisioning strategy is suitable for use on both open and mainframe systems. Virtual LVI or
Virtual LUN software is required to configure variable-sized provisioning.
Virtual LVI/Virtual LUN functions
Virtual LVI or Virtual LUN functions are used to create, configure, or delete a customized volume
(LDEV).
In this manual, the Virtual LUN and the Virtual LVI function are collectively referred to as VLL. The
only difference between the two functions is that Virtual LUN is an open systems function available
in Open Volume Management software, while Virtual LVI is a mainframe function available in
Virtual LVI software.
A parity group usually consists of some fixed-sized volumes (FVs) and some free space. The number
of FVs is determined by the emulation type. A VLL volume usually consists of at least one FV, one
or more customized volumes (CVs), and some free space.
You can use VLL to configure variable-sized volumes that efficiently exploit the capacity of a disk.
Variable-sized volumes are logical volumes that are divided into smaller size than normal (fixed-size)
volumes. This configuration is desirable when frequently accessed files are distributed across smaller
multiple logical volumes. This generally improves the data accessing performance, though file
access may be delayed in some instances.
VLL can also divide a logical volume into multiple smaller volumes to provide space efficiencies
for small volumes such as command devices. Thus, VLL can efficiently exploit the capacity of a disk
by not wasting capacity using larger volumes when they are not needed.
VLL requirements
Use of Virtual LVI or Virtual LUN on the P9500 storage system to configure variable-sized volumes
requires the following:
•
A license key on the Remote Web Console computer for Virtual LUN. This is available in Open
Volume Management, software and is for open systems.
For details about the license key or product installation, see the HP P9000 Remote Web Console
User Guide.
VLL specifications
“Virtual LUN specifications for open systems” (page 44)
“CV capacity by emulation type for open systems” (page 45)
Virtual LUN specifications for open systems
Open system Parameter
OPEN-3, OPEN-8, Emulation type
OPEN-9, OPEN-E, OPEN-V
Depends on the track geometry Ability to intermix emulation type
2,048 for RAID5 (7D+1P) or RAID6 (6D+2P) Maximum number of volumes (normal and
Virtual LUN) per parity group
1,024 for other RAID levels
44 Configuring custom-sized provisioning