More versions means Duplicati has to track more and more data about your backups. This could cause the sqlite database to get larger and make operations take longer.
I would consider automatically pruning older versions. Duplicati can support a robust retention policy that automatically reduces the number of versions the older they get. This is what I personally use:
--retention-policy="7D:U,3M:1D,2Y:1W,U:1M"
This means:
- For the most recent 7 days, keep unlimited (all) backups
- After that, for the most recent 3 months, keep 1 backup per day
- After that, for the most recent 2 years, keep 1 backup per week
- After that, for an unlimited amount of time keep 1 backup per month
You can of course adapt to your liking. The custom retention policy option can be seen on page 5 of the backup job configuration:
The built in scheduler doesn’t provide support for that. Some have been able to do it using a custom script that runs before the backup job and tells Duplicati to not run the backup if it’s outside of a certain time window. Here’s an example script for Windows: Feature request: Better scheduling with Duplicati - #8 by drwtsn32