What is an incremental backup?
Plesk supports two types of backup:
-
Full. Each time you create a backup, the backup includes all data
regardless of the time when the data was last updated. -
Incremental. An incremental backup contains only the data that has
changed since the time of the last backup.
Using incremental backups significantly reduces the duration of a backup
operation, CPU load, and the disk space occupied by backup files, and,
therefore, improves the backup performance.
Plesk includes the following data in incremental backups:
- Web hosting data changed since the time of the last backup (full and
incremental). - Mail data changed since the time of the last backup (full and
incremental). - Full backup of database data.
Note that incremental backups contain whole files created on a
subscription, not their parts. Plesk determines whether the data has
been changed based on whole files. For this purpose, Plesk uses an index
file that is created for each backup at the time of backup creation. The
index file lists all files that existed in a subscription, and
information about them, such as size, modification date, permissions or
owner. A full backup lists all files, while an incremental one may list
just a few files that have changed. The listed files are those included
into a backup.
How Plesk determines whether to include a file into a backup:
- The file was absent in the index for previous backups (full and
incremental). - The file’s size or modification time are different from those in the
index for the previous backup. - The file’s permissions or owner are different.
How to create an incremental backup
To create a backup, go to the Backup Manager page (of the server,
user account, or subscription, correspondingly) and click the Back
Up button. Then you can select a type of a backup: Full or
Incremental. When you back up your data for the first time, it is
always a full backup no matter what type of backup is selected. If you
create a subsequent backup of the Incremental type, only the web
hosting data and mail data that has changed since the last backup is
saved. As a result, you can have a full backup and a sequence of several
incremental backups.
Incremental backups are listed on the Backup Manager page with the
Incremental label.