4 Configuring custom-sized provisioning
Abstract
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.
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 45)
“CV capacity by emulation type for open systems” (page 46)
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
45