Managing Backup Policies (Classes)
77
3
the backup time. The maximum jobs attributes must be set to allow the parallel
backups and sufficient system resources must be also available (“Number of
Concurrent Streams” on page 73 provides an explanation of maximum jobs
settings that also applies to this discussion).
Note:
Understanding disk and controller I/O limitations is important when
using multiple classes for a client. For example, if there are two file systems
that will overload the client when backed up in parallel, place them in the
same class, schedule them at different times, or set Maximum Jobs Per Client to
1.
Another way to reduce backup time is to use a single class that has Allow
Multiple Data Streams enabled and then add
NEW_STREAMS
directives to the
file list. For example:
NEW_STREAM
file_a
file_b
file_c
NEW_STREAM
file_d
file_e
file_f
This produces two concurrent data streams. One has
file_a
,
file_b
, and
file_c
. The other has
file_d
,
file_e
, and
file_f
. For more information,
see “Allow Multiple Data Streams” on page 70.
Note:
For best performance, use only one data stream to back up up each
physical device on the client. Multiple concurrent streams from a single
physical device can adversely affect backup times.
NetBackup 3.2 System Administrator's Guide for Windows NT
NetBackup 3.2 System Administrator's Guide for Windows NT
