Planning a Backup and Restoration of Files for Disaster Recovery
Planning a backup and restoration of files is the most important step to protect
data from accidental loss in the event of data deletion or a hard disk failure.
The backup copy can be used to restore lost or damaged data.
For taking backups and restoring files, Microsoft has provided a utility called
Backup. The Backup utility creates a copy of data on a hard disk of a computer and
archives data on another storage media. Any storage media such as removable disks,
tapes, and logical drives can be used as a backup storage.
While taking a backup of files, the Backup utility creates a volume shadow copy
of the data to create an accurate copy of the contents. It includes any open
files or files that are being used by the system. Users can continue to access
the system while the Backup utility is running without the risk of losing data.
Volume Shadow Copy
Backup provides a feature of taking a backup of files that are opened by a user
or system. This feature is known as volume shadow copy. Volume shadow copy makes
a duplicate copy of all files at the start of the backup process. In this way,
files that have changed during the backup process are copied correctly. Due to
this feature, applications can continue writing data to the volume during a
backup operation, and backups can be scheduled at any time without locking out users.
Types of Backups
The Windows Backup utility provides various types of backups. While planning for
a backup strategy, it is important to choose an appropriate type or combination
of different types of backups. The backup type determines which files are
transferred to the destination media.
Each backup type relates to an attribute maintained by every file known as
archive (A). The archive attribute is set when a file is created or changed.
When an archive attribute is set, it means that the backup of this file has not
been taken or it is due.
Note: When it is said that "The file is marked as backup", it means that the
archive attribute of the file has been cleared.
When an administrator chooses to use a normal backup, all selected files and
folders are backed up and the archive attribute of all files are cleared. A
normal backup does not use the archive attribute to determine which files to
back up. A normal backup is used as the first step of any backup plan. It is
used with the combination of other backup types for planning a backup strategy
of an organization. Normal backups are the most time-consuming and are resource
hungry. Restoration from a normal backup is more efficient than other types of backups.