Snapshot And Direct I/O Support For Unix - Computer Associates ARB6002700WF0. ..... - BRIGHTSTOR ARCSERVE 2000 Manual

Snapshot and Direct I/O Support for UNIX

Snapshot and Direct I/O Descriptions
UNIX client agents support the Snapshot and Direct I/O features. To take
advantage of these features, one of the following environments must exist on
the machine running the UNIX client agent:
Feature Platform
Snapshot Solaris
Snapshot HP-UX 11.0
Direct I/O Solaris
Direct I/O HP-UX 11.0
With Direct I/O, the client agent takes a snapshot on advanced versions of
VxFS, Online JFS (HP-UX), and UFS with fssnap installed on Solaris. The client
agent mounts the snapshot to a temporary directory created in the root
volume, and then generates the snapshot backup. After the snapshot backup
is complete, the client agent dismounts from the temporary directory and
deletes the snapshot.
To perform a snapshot backup, you must specify a snapshot buffer. A
snapshot buffer is the disk space used to store the original data before it is
overwritten in the snapped volume. Remember these considerations when
using the snapshot buffer:
The snapshot buffer needs to be large enough to store all the data that
changes in the snapped volume for the duration of the backup. If the
snapshot buffer runs out of space, the snapshot becomes invalid and the
backup fails.
The snapped volume and the snapshot buffer should not be on the same
file system.
For better performance, the snapped volume and the snapshot buffer
should be on separate physical disks.
For UFS on the Solaris platform (using fssnap), the snapshot buffer can be
a file name, a directory name, or a raw partition.
UNIX, Linux, and Mac OS X Client Agent Configuration File
Software Requirements
UFS file system with the fssnap package
installed (Solaris 8 and 9) or the advanced
version of VxFS file system.
Advanced version of VxFS file system or
Online Journaling File System (JFS).
UFS file system or VxFS file system.
Advanced version of VxFS file system or
Online JFS.
Adding and Configuring the Client Agents 49