HP Data Protector Express Basic-Software - Manual (Page 61)

CAUTION:
These .log files are then purged.
When the Backup mode is set to Differential, for databases, only the .log files are included in the
backup job, but these files are not purged.
When the Backup mode is set to Copy, Data Protector Express runs the job similar to full backup.
However, the transaction logs are not purged at then of a job run in Copy mode.
Backup modes and circular logging
Microsoft Exchange Server supports database circular logging. Circular transaction logs differ from
normal logs in that only a few log files are maintained. These files are purged automatically as new log
files are created. When the transactions in the circular log files are recorded in the database, the log files
are then deleted. New transactions are recorded in newly created log files.
If circular logging is enabled, you cannot do incremental or differential backups. These backup modes
rely upon past transaction logs and thus are not available when circular logging in enabled. When
circular logging in enabled, Data Protector Express will revert to full backup mode.
You can check to see if circular logging in enabled for a particular server by examining the Advanced
tab of that server’s Properties window. If you turn circular logging off, Microsoft Exchange Server will
stop the database service and restart it after making the changes.
Restoring Microsoft Exchange Databases
To restore the Microsoft Exchange Server databases, you must restore the database files and all of the log
files created since the last full backup job. To do so, you either (1) restore the databases from the last
full backup if the last backup (the previous day’s) was a full backup; (2) restore the databases from the
most recent full backup and the last differential backup if the last backup was a differential backup; or
(3) restore the databases from the last full backup and all of the incremental backups made between
that day and the present day.
To restore a Microsoft Exchange server, see
Disaster Recovery with Microsoft Exchange Server .
NOTE:
When you restore the databases, you must create and run a separate job for each set of transaction logs
you need to restore. You cannot skip any logs and the logs must be restored in sequential order. Thus,
when recreating the databases, you must first restore the actual databases (created by a backup job
running in full backup mode). Next, you must restore the transaction logs in the order created and in
separate jobs. No log can be skipped when restoring.
For example, if you did a full backup on Monday and incremental backups each day Tuesday through
Friday, in order to restore the databases to their state at the close of business Friday, you must run
five separate jobs: one restoring the actual databases from Monday’s full backup job and then four
additional separate jobs restoring each transaction log in sequential order, beginning Tuesday and
continuing with each log sequentially until Friday.
To restore the Microsoft Exchange Server Databases
1.
Find the date of the last full backup of the databases.
2. Create a restore job.
3. On the Selection property page, locate and select the Microsoft Exchange Server storage group.
4. In the Versions of window, click the Details button.
User’s Guide 61