First, I would like to express my appreciation and gratitude to all who have spent their time creating and improving Duplicati; it is an excellent piece of software.
I use Duplicati to keep daily backups of several Hyper-V .VHDX disk images totaling just over 1 TB in size. Occasionally the compaction process can take a very long time to complete - so much so that it’s still running when the next day’s scheduled backup is supposed to start.
I have tried lowering the compaction threshold with the intention of having the compaction run more frequently, in the hopes it would have less work to do when it runs. It seems to have helped, but every now and then it starts compacting and despite having no storage or bandwidth constraints it’s still running 24+ hours later.
It would be useful to be able to set a time limit for the compaction operation so that it can’t run so long that it interferes with other backup jobs.