The Merge functionality is definitely present in urBackup, e.g. it’s used for restoring a backup. For this reason, before another backup occurs, the backups are definitely merge. The only thing I am not sure about is, which backups are merged. But that is easy enough to find out… will be doing a test soon.
UPDATE: Just did a test. So what happens is, that it does a full back-up – while calling it an incremental back-up. In other words, it now says that it has one full back-up and two incremental back-ups, but the newest incremental back-up is actually a full back-up.
This seems inefficient. A cheap SSD will wear out much sooner if it does full back-up instead of merging previous incremental with last full back-up and doing a new incremental.
Most of the times, only tiny amount of files are changed between two incremental backups. So better approach is that it merges 1st incremental with the last full back-up and do a new incremental. This will save network bandwidth and disk resources very much
