How incremental backups work on UNIX?
I understand to back up UNIX clients, NetBackup compares mtime of the files to see if an incremental backup is needed. Let's say file1
- was modified on 1/1
- was backed up by a full backup on 1/2
- was modified on 1/3
- an incremental will be done on 1/4
During the incremental backup, does NetBackup compare 1/3 with 1/2? Where does it find the information about 1/2? from the catalog? or the last full backup start time, end time?