When the chain of incremental backups in an archive becomes long, conversion of an incremental backup to a full one increases the reliability of your archive. You may also want to convert a differential backup if there are incremental backups that depend on it.
During the conversion, the selected incremental or differential backup is replaced with a full backup for the same point in time. The previous backups in the chain are not changed. All subsequent incremental and differential backups up to the nearest full backup are also updated. The new backup versions are created first and only after that are the old ones deleted. Therefore, the location must have enough space to temporarily store both the old and the new versions.
Conversion does not create a copy of a backup. To obtain a self-sufficient copy of the backup on a flash drive or removable media, use the export operation.
Example
You have the following backup chain in your archive:
F1 I2 I3 I4 D5 I6 I7 I8 F9 I10 I11 D12 F13
Here F means full backup, I -incremental, D - differential.
You convert to full the I4 backup. The I4, D5, I6, I7, I8 backups will be updated, while I10 I11 D12 will remain unchanged, because they depend on F9.
Limitation: The Convert to full backup operation is not allowed for backups on tapes and CD/DVD.