You don’t need the
-keep 1:60; the 30, 60, 90 days interval is already handled by the
-keep 30:30. This is how you should read the each parameter:
-keep 30:30 # Keep a revision every 30 days for revisions older than 30 days
Where the first number is
interval (gap between consecutive revisions to keep), and the second number is
age. The various
keep's must be sorted by decreasing age.
So as you’re doing daily backups, this is enough:
-keep 0:90 -keep 30:30
Though keep in mind your 90 day old backup will suddenly get deleted (after it reaches 91 days age) and then your oldest backup becomes 61 days old. If you want to keep a backup that’s always at least 90 days old, consider changing the first
-keep 0:120 or longer.
De-duplication should keep the storage size down. Many of us have much longer retentions, and personally I don’t delete anything not even have 3 years or so.