Data Protection for Exchange supports different types of database backups: a full backup, copy backup, incremental backup,
and differential backup. You can complete these types of database backups within a Volume Shadow
Copy Service (VSS) framework that provides a common interface model for generating and managing
online snapshots.
Data Protection for Exchange backup
types are as follows:
- Full backup (VSS)
- A full backup backs up the specified database and associated transaction
logs. The Exchange Server deletes the committed log files after
the integrity of the database and logs are verified and backed
up. If the database is not mounted, the backup fails and the transaction
logs are not truncated.
- Copy backup (VSS)
- A copy backup is similar to a full backup except that transaction
log files are not deleted after the backup. A copy backup is
used to create a full backup of the Exchange Server database
without disrupting any backup procedures that use an incremental or
differential backup.
- Incremental backup (VSS)
- An incremental backup backs up only transaction logs. The Exchange
Server deletes the committed log files after the files are successfully
backed up. These log files are not deleted if the backup fails.
Restoring an Exchange Server database from an incremental backup
requires the following tasks:
- Restore of the last full backup
- Restore of any other incremental backups that are performed between
the full backup and the incremental backup
- Restore of the incremental backup
The log files are not deleted if databases are not mounted.
- Differential backup (VSS)
- A differential backup backs up transaction logs. The log files
are not deleted. When you run a full backup followed by only
differential backups, the last full backup and the latest differential
backup contain all the data that is required to bring the database
back to the most recent state. This type of backup is also called
a cumulative incremental backup.
Restoring an
Exchange Server database from a differential backup requires the
following tasks:
- Restore of the last full backup
- Restore of this differential backup, but no other differential
backups
When circular logging is enabled, you cannot
use differential or incremental backups. Data loss might occur
if the log wraps before an incremental or differential backup finishes.
If you choose a backup strategy that involves incremental or differential
backups, you must disable circular logging for the Exchange database.
For more information about circular logging, see theMicrosoft Exchange Server documentation.