White Papers

BP1013 Best Practices for Enhancing Microsoft Exchange Server 2010 Data Protection and Availability 27
7 Recovery scenarios
As we showed how EqualLogic Smart Copy snapshots can be taken in an Exchange environment and
overall what the efficiency and the cost will be in term of local host resources, we moved forward in
the test plan to verify the recovery scenarios that will directly benefit from the use of these Smart Copy
snapshots.
Remember that backup applications integrated in the Microsoft VSS framework, such as Symantec
Backup Exec or CommVault Simpana powering a Dell PowerVault DL2200 backup-to-disk appliance,
can directly request, create, and access Shadow Copies residing on EqualLogic Smart Copy snapshots.
The Exchange database and logs can then be backed up directly from a Smart Copy snapshot through
the backup media server accomplishing the result of off-loading host resources and reducing
consistently, up to eliminating, the backup windows and the overlap with the activities of users. The
integration of such technologies with the EqualLogic Smart Copy technology completes the set of
functionalities required in a recovery scenario and provides an end-to-end protection solution.
7.1 Backup mechanisms applied to Exchange recovery
Different backup technologies allow recovering Exchange with different approaches. The method of
backup for the store elements of Exchange defines the techniques of possible recovery. Traditional
backup types are as follow:
Full Sometimes identified as reference or image, it represents a full point-in-time copy of the
store elements selected within the backup catalog.
Advantages A backup set contains all the required data for recovery.
It is operationally easier to restore.
Disadvantages A backup set can have large capacity requirements.
It requires a longer backup window.
Incremental Provides a copy of the store elements that have changed since, or were not present at
the time of the last incremental or full backup.
Advantages It requires less space, proportional with the change-rate of the data.
It requires shorter backup windows.
Disadvantages It is operationally more complicated to restore, more backup sets.
It requires more time to be restored, proportional with the number of
backup sets.
It requires the entire sequence of backup sets to be restored.
Differential Provides a copy of the store elements that have changed since, or were not present at,
the time of the last full backup.
Advantages It provides balanced window backup and capacity requirements.
It requires only two backup sets for a restore (full and differential).
Disadvantages The balance of time and capacity can still be unacceptable if more
than one differential is taken before the next full backup.
When applied to a transactional database, such as Microsoft Exchange, incremental and differential
backups have been strengthened by transaction log technologies. Performing an incremental or