Capacity Management Features; Volume Groups; Disk Groups - HP Surestore Disk Array 12h - And FC60 Service Manual

Capacity Management Features

The disk array uses a number of features to manage its disk capacity efficiently. Volume
groups allow you to partition the total disk capacity into smaller, functional entities.
Caching improves disk array performance by using controller RAM to temporarily store
data during I/Os.

Volume Groups

The capacity of the disk array can be divided into entities called volume groups. Individual
disks are grouped together to form a volume group. Functionally, each volume group
appears to the host operating system as an individual disk drive.
Although the volume group appears to the host as an individual disk, the use of multiple
disks offers advantages of increased data availability and performance. Data availability is
enhanced by using redundant data stored on a separate disk from the original data. The use
of multiple disks increases performance by allowing simultaneous access to several disks
when reading and writing data.

Disk Groups

A disk group is a collection of individual disks that share a common role in disk array
operation. All disks on the disk array become a member of one of the following disk
groups:
•
Volume group - Each volume group on the disk array has its own disk group. When a
disk is included as part of a newly created volume group, the disk becomes a member
of the associated disk group.
•
Hot spare group – All disks assigned the role of global hot spare become members of
this group. Up to six disks (one for each channel) can be assigned as global hot spares.
•
Unassigned group – Any disk that is neither part of a volume group nor a global hot
spare is considered unassigned and becomes a member of this group. Unassigned disks
can be used to create a volume group or can be used as global hot spares. Unassigned
disks do not contribute to the capacity of the disk array.
Capacity Management Features
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