backup_increment.html

<header>Backup Level</header>

By default, Virtualmin backups will include all files in the selected domains'
home directories. However, if you regularly backup large virtual servers,
a lot of time may be spent copying files that have not changed recently. <p>

If the <b>Differential</b> option is selected here, only those files that
have changed or were created since the last full backup will be included.
This is most useful when you have two scheduled backups, such as a weekly
full backup and a daily differential. Assuming that most files in a domain
are un-changed day to day, this will substantially reduce the size and
time of daily backups. <p>

Be aware that when restoring, you will need to restore first the full backup
and then the differential to recover all files. Also, other data such as 
Apache configurations and databases is not differentially backed up, and
so will always be included regardless of this option. <p>

The <b>Neither</b> option also performs a full backup, but does not change
the backup state. This can be useful when performing an ad-hoc
backup of domains that also have full and differential backups scheduled. <p>

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