HP XP Racks - Manual (Page 43)

4 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.
Virtual LUN functions
Virtual LUN function is used to create, configure, or delete a customized volume (LDEV).
The Virtual LUN function is an open systems function available in Open Volume Management
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 Virtual LUN volume usually consists of at least one
FV, one or more customized volumes (CVs), and some free space.
You can use the Virtual LUN function to configure variable-sized volumes that efficiently exploit the
capacity of a disk. Variable-sized volumes are logical volumes that are divided into smaller 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.
The Virtual LUN function can also divide a logical volume into multiple smaller volumes to reduce
unused capacity and provide a more efficient use of space for small volumes such as command
devices. The Virtual LUN function can efficiently exploit the capacity of a disk by not wasting
capacity using larger volumes when the extra capacity is not needed.
Virtual LUN requirements
Use of Virtual LUN on the HP XP7 Storage to configure variable-sized volumes requires the following:
•
A license key 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 XP7 Remote Web Console
User Guide.
Virtual LUN specifications
“Virtual LUN specifications for open systems” (page 43)
“CV capacity by emulation type for open systems” (page 44)
Virtual LUN specifications for open systems
Open system Parameter
OPEN-V OPEN-3, OPEN-8, OPEN-9, OPEN-E Track format
OPEN-V OPEN-3, OPEN-8, Emulation type
OPEN-9, OPEN-E
Depends on the track geometry Depends on the track geometry Ability to intermix emulation type
2,048 for RAID 5 (7D+1P), RAID 6
(6D+2P), or RAID 6 (14D+2P) 2,048 for RAID 5 (7D+1P), RAID 6
(6D+2P), or RAID 6 (14D+2P) Maximum number of volumes
(normal and Virtual LUN) per
parity group
1,024 for other RAID levels 1,024 for other RAID levels
65,280 65,280 Maximum number of volumes
(normal and Virtual LUN) per
storage system
Virtual LUN functions 43