TMF Planning and Configuration Guide (H06.05+)

Configuring TMF for Backup and Recovery
HP NonStop TMF Planning and Configuration Guide—540136-002
5-4
Optimizing Online Dumping
will never have more than a week’s worth of audit information to reapply to any
damaged tables or files.
Optimizing Online Dumping
Because you can make online dumps even while the database is being updated, you
can schedule them whenever it is convenient for your business. Because making
online dumps consumes system resources, it could noticeably affect transaction
processing; therefore, you might want to schedule online dumps during hours when
activity is low.
Performing both batch processing and online transaction processing against the same
database can affect the optimum scheduling of online dumps. If most updating is
performed by your batch applications, you might want to schedule online dumps after
the batch updating is complete. If file recovery is needed, your online dumps would
then reflect the batch updates, and only the changes made by the online transaction
processing application would have to be redone by the file recovery process.
There are two other things you can do to optimize online dumping:
1. Dump your tables and files a volume at a time (DUMP FILES $DATA4.*.*).
2. Distribute online dumping evenly throughout the week and make the dumps during
a period of relatively light system activity (in the early evening, for example).
If your system includes 20 data volumes, for example, dump four of them each day, on
a rotating basis.
Managing Audit Dumps
An audit dump is a copy of an audit-trail file written to secondary storage media (such
as tape) by an audit dump process. Audit dumps preserve audit-trail files for use by
the file recovery process. If you configure and enable automatic audit dumping, an
audit dump occurs automatically whenever an audit-trail file becomes full and is no
longer needed by outstanding transactions or volume recovery. The TMF catalog
retains audit dumps for as long as they are required by any online dump.
Although you can direct them to disk, audit dumps are most often recorded on
magnetic tape. Because dumping to tape requires operator intervention, your audit
dump strategy in that situation is necessarily more involved and more critical than if
you are dumping to disk.
Your tasks in managing audit dumps are as follows:
•
Become familiar with how often audit-trail files become full on your system so that
you can plan for audit dumps.
•
Configure the automatic audit dumping feature.
•
Pause and resume (enable and disable) automatic audit dumping if needed.
(You might want to leave it enabled all the time.)