HP B6960-96035, Concepts Manual

Page: 275 / 422

13 Snapshot concepts
In this chapter
This chapter introduces the snapshot backup concepts and discusses the configurations
that are supported by HP.
It is organized as follows:
“ Overview ” on page 275F
“ Supported configurations ” on page 281
Overview
The rapidly expanding requirement for high availability storage configurations has
led to the introduction of new zero downtime backup (ZDB) technologies. The
advances in storage virtualization technology have provided the opportunity for an
alternative to conventional split mirror technology.
Within the Data Protector ZDB solution, different disk array technologies are combined
with the latest developments in the snapshot technology, to create snapshots of
application or database data stored on a disk array. These snapshots can
subsequently be kept on a disk array as point-in-time copies of the original data for
instant recovery purposes or can be used to produce ZDB-to-tape sessions on a
backup system. The processes concerned have minimal impact on the application
server, providing an effective ZDB solution.
Storage virtualization
The term “storage virtualization” is used to describe the technology that separates
the logical representation of storage from the actual physical storage components.
This means the creation of logical volumes out of a pool of physical disks residing
in a disk array. A logical volume is limited by the boundaries of the pool, but may
span over any number of physical disks within the disk array. Logical volumes can
be presented to one or multiple host systems. You cannot have control over the exact
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