How to set that backups are never deleted?

[coezbek]

I would have assumed that putting 0 into the number of backups to keep does this, but it isn't mentioned in the docs.

Can you confirm?

[marvinweber]

No, in the current implementation setting this to 0 will delete all backups.
This obviously does not make sense, it should be changed to either not delete any backups when setting to 0 or providing a checkbox and not allowing a setting of 0.

In the meantime, as a workaround, you can set the limit to a very high number you'd probably never reach...