Tuesday, 15 January 2013
1/15/2013 10:20:00 pm 0

What is the need to backup Exchange server database?

Exchange server stores all the mailbox data in EDB file format. Like other data file formats this file is also prone to corruption. So, to avoid any disastrous or data loss situations it’s advisable to backup the Exchange data on regular basis. Creating the Backup of data is the best way to ensure that if any kind of data loss or corruption occurs then, you have some alternative to restore your data back without hampering the work. 

Before we go to the Steps for ‘Exchange Backup’ procedure, we must be aware of the backup methods that can be performed with Exchange server.

There are two types of Exchange Server Backup Methods:
1. Online Backup method
2. Offline Backup method

1. Online Backup
While performing Online backup of Exchange Server databases there is no need to shut down the Exchange server or stop any Exchange services.

Patch file: An Exchange Patch file is signified by .pat format. The main purpose of the patch files is to ensure that the pages that are modified during backup are also backed up, it is accomplished by tracking and recording any modification being done to the pages while the backup process is going on.

Two patch files used are:
  • Priv.pat: It is used for the tracking private information store.
  • Pub.pat: It is used for the tracking public information store.
The four types of Backups are:
1.Normal (or Full) backup: It backups the whole Exchange or directory store, including the log files.
2.Incremental backup: It only backups the components changed after the last normal or incremental backup. 
3.Differential backup: It backups the changes since the last normal backup. 
4.Copy backup: It is similar to normal backup except that there is no marking with regards to incremental and differential backup context. 

2. Offline Backup
While performing offline backup Exchange server database and all Exchange services are shut down.
Planned offline backups are done whenever there is a preplanned server shutdown.
If the server fails then, the backups taken in that case are termed as unplanned offline backups. 

There are several benefits of ‘Online Backup’ over ‘Offline Backup’ such as:
  • You can validate the checksum on each database page while performing online backup which is not possible in case of offline backup.
  • As online backup is done by using backup program so, its needs less management and involvement from the user side but offline backup is prone to human errors because it is done manually.
It is not preferred to take offline backup of Exchange server as it might hamper the normal functioning of the organization. But if there is a planned shutdown of Exchange server then, you may chose offline backup.
Otherwise it’s always preferable to use online backup process so, that all work can also continue side by side of the backup procedure.


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