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the same full backup at the same point of time. The above mentioned difference implies creating a
differential backup after (or instead of) creating multiple incremental backups.
An incremental or differential backup created after disk defragmentation might be considerably larger than
usual because defragmentation changes file locations on the disk and the backup reflects these changes. It is
recommended that you re-create a full backup after disk defragmentation.
The following table summarizes the advantages and shortcomings of each backup type as they
appear based on common knowledge. In real life, these parameters depend on numerous factors
such as the amount, speed and pattern of data changes; the nature of the data, the physical
specifications of the devices, the backup/recovery options you set, to name a few. Practice is the
best guide to selecting the optimal backup scheme.
Parameter
Full backup
Differential backup
Incremental backup
Storage space
Maximal
Medium
Minimal
Creation time
Maximal
Medium
Minimal
Recovery time
Minimal
Medium
Maximal
3.4 What does a disk or volume backup store?
A disk or volume backup stores a disk or a volume file system as a whole, along with all the
information necessary for the operating system to boot. It is possible to recover disks or volumes as a
whole from such backup, as well as individual folders or files.
With the sector-by-sector (raw mode) option enabled, a disk backup stores all the disk sectors.
For supported file systems, with the sector-by-sector option turned off, a disk or volume backup
stores only those sectors that contain data. This reduces the resulting backup size and speeds up the
backup and recovery operations.
Windows
The swap file (pagefile.sys) and the file that keeps the RAM content when the machine goes into
hibernation (hiberfil.sys) are not backed up. After recovery, the files will be re-created in the
appropriate place with the zero size.
A volume backup stores all other files and folders of the selected volume independent of their
attributes (including hidden and system files), the boot record, the file allocation table (FAT) if it
exists, the root and the zero track of the hard disk with the master boot record (MBR). The boot
code of GPT volumes is not backed up.
A disk backup stores all volumes of the selected disk (including hidden volumes such as the
vendor's maintenance partitions) and the zero track with the master boot record.
Linux
A volume backup stores all files and folders of the selected volume independent of their
attributes; a boot record and the file system super block.
A disk backup stores all disk volumes as well as the zero track with the master boot record.