How Immutability for Linux Works
The count of the immutability period indicated in the backup repository settings starts from the moment the last restore point in the active chain is created. The immutability period is extended only for the active backup chain.
The full backup file of the active backup chain was created on January 12. The first increment was created on January 13. The second and last increment was created on January 14.
The immutability period indicated at the backup repository settings is 10 days.
The backup files will be immutable until January 24: the date of the last restore point creation (January 14) + 10 days.
Standard backup files
The immutability period for each standard backup file in the active backup chain is set according to the backup repository settings (7 days by default).
GFS backup files
If the backup repository is part of a scale-out backup repository with the capacity tier added, the immutability period for full backup files with GFS retention policy is set according to the backup repository setting.
Otherwise, the following periods will be compared: the immutability period set for the backup repository and the GFS backup file lifetime. The immutability period for full backup files with GFS retention policy will equal the longest of these periods.
The backup repository immutability period is 10 days. The GFS backup file lifetime is 3 years. The backup file will be immutable for 3 years.
The increments from this full backup file will be immutable for 10 days from the moment of the last increment creation.