3.2.1. Arranging backup requirements¶
There are various requirements related to backup. When considering the optimal backup method for your environment, it is necessary to decide what needs to be backed up and how backup needs to be done.
In this section, we explain reference information for deciding target of backup and what type of backup is available.
(1) Organize target of backup. (Consideration of capacity that is required for backup)
Target | Usage application |
Unit of disk/volume
(Image backup)
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Unit of file/folder
(File backup)
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* It is necessary to consider the retention period of the archive that was backed up.
(2) Organize type of backup. (Consider the length of time that is required for backup.)
Type | Description | Advantages | Disadvantages |
Complete | All target data are imported and these data are used as basis of incremental backup and differential backup. | Recovery can be done independently so that the recovery time is short. | Backup time is long.
Backup size is large.
|
Incremental | Only changes are imported.
At the time of restoration, all incremental backup and the latest complete backup are used.
|
Backup time is short.
Backup size is small.
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If there are multiple incremental backup, data cannot be restored if one backup is damaged. |
Differential | Only changes from the last complete update are imported.
At the time of restoration, the latest incremental backup and the latest complete backup are used.
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Backup time is short. (Backup time is longer than the incremental backup)
Backup size is small. (Larger than the incremental backup)
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If backup is frequently performed from the last complete backup, the backup size becomes large. |