I've just started using FFS (v14.2). A strange thing that I've observed is that FFS apparently creates a lock file during synchronization, even though that particular directory root does not have a single file that needs synchronizing (as determined by a prior compare step).
Example:
In that particular example, I ran a Comparison action first (F5 key) and after that a Synchronization action (F9 key). FFS creates a lock file at M:\Photos (see text in popup), even though the two pairs using M:\Photos on the left side don't have a single file that is different (see Overview pane on the bottom right).
Does FFS rerun the Comparison step, when I run the Synchronization step? If it doesn't, then it should ideally only create lock files, if there are actually any changes to sync for that directory.
FFS doesn't re-run the compare, but it will lock every root location regardless of the presence of file changes. This would be a new feature request, but there's need to be a good reason for it
FFS locks the root locations when starting the Compare phase.
At that time FFS still needs to determine if any sync actions are required for any of its locations.
Only after the Compare phase, FFS could potentially (already) remove the lock-file for those locations not requiring any sync actions.
I suppose for simplicity the FFS author choose to always remove lock-files only after the actual sync has completed.
Note that you can not disable the use use of lock-files by setting the LockDirectoriesDuringSync flag to "false"). Make sure to read the risk when doing so.
