VERITAS FlashSnap Point-In-Time-Copy Solutions Administrator's Guide

1
Point-In-Time Copy Solutions
1
This chapter introduces the point-in-time copy solutions that you can implement using the
VERITAS FlashSnap
TM
technology.
Note To implement the Point-In-Time Copy solutions presented in this document, a valid license
for VERITAS FlashSnap must be present on all the systems to which the solutions are
applied.
VERITAS FlashSnap offers a flexible and efficient means of managing business critical data. It
allows you to capture an online image of actively changing data at a given instant: a point-in-time
copy. You can perform system backup, upgrade and other maintenance tasks on point-in-time
copies while providing continuous availability of your critical data. If required, you can offload
processing of the point-in-time copies onto another host to avoid contention for system resources
on your production server.
Two kinds of point-in-time copy solution are supported by the FlashSnap license:
◆ Volume-level solutions are made possible by the Persistent FastResync and Disk Group
Split/Join features of VERITAS Volume Manager. These features are suitable for
implementing solutions where the I/O performance of the production server is critical.
The Persistent FastResync and Disk Group Split/Join features are described in “Persistent
FastResync of Volume Snapshots” on page 6 and “Disk Group Split/Join” on page 7.
◆ File system-level solutions use the Storage Checkpoint feature of VERITAS File System.
Storage Checkpoints are suitable for implementing solutions where storage space is critical
for:
◆ File systems that contain a small number of mostly large files.
◆ Application workloads that change a relatively small proportion of file system data blocks
(for example, web server content and some databases).
◆ Applications where multiple writable copies of a file system are required for testing or
versioning.
The Storage Checkpoints feature is described in “Storage Checkpoints” on page 8.
The FlashSnap license also supports the VERITAS FlashSnap Agent for Symmetrix. This feature is
described in “VERITAS FlashSnap Agent for Symmetrix” on page 8.