Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

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Configuring Off-Host Processing
11
Note The FastResync feature is not supported by VxVM 4.1 on the HP-UX 11i v3
platform.
Off-host processing allows you to implement the following activities:
◆ Data Backup—As the requirement for 24 x 7 availability becomes essential for many
businesses, organizations cannot afford the downtime involved in backing up critical
data offline. By taking a snapshot of the data, and backing up from this snapshot,
business-critical applications can continue to run without extended down time or
impacted performance.
◆ Decision Support Analysis and Reporting—Because snapshots hold a point-in-time copy
of a production database, a replica of the database can be set up using the snapshots.
Operations such as decision support analysis and business reporting do not require
access to up-to-the-minute information. This means that they can use a database copy
that is running on a host other than the primary. When required, the database copy
can quickly be synchronized with the data in the primary database.
◆ Testing and Training—Development or service groups can use snapshots as test data
for new applications. Snapshot data provides developers, system testers and QA
groups with a realistic basis for testing the robustness, integrity and performance of
new applications.
◆ Database Error Recovery—Logic errors caused by an administrator or an application
program can compromise the integrity of a database. By restoring the database table
files from a snapshot copy, the database can be recovered more quickly than by full
restoration from tape or other backup media.
Off-host processing is made possible by using the FastResync and disk group move, split
and join features of VxVM. These features are described in the following sections.
You can also use such solutions in conjunction with the cluster functionality of VxVM.
For implementation guidelines, see “Implementing Off-Host Processing Solutions” on
page 317.