BUG: not enough free space

[raven]

Synchronized Mode: Mirror
Free space on the destination disk: 3 GB
There is a file on the destination drive size of 3.6 GB, which is necessary to replace the file from the source size of 3.7 GB.
When you start synchronizing get the error "not enough space to copy the file."
"Ignore" button - simply excluded this file from synchronization. [x] "Delete files permanently" in the sync settings did not change anything.

I had to manually delete the file on the destination drive, for successful synchronization.
Please fix this problem.
Sorry for my bad ENG (Google Translate).

[Zenju]

FreeFileSync optimizes the sequence of synchronization steps so that peak disk space usage is reduced as far as possible (e.g. it starts by overwriting larger files by smaller ones first and deleting files that only exist on the target side), however there are more settings that temporarily affect disk space:

1. Menu -> Tools -> Options: "Fail-safe file copy". Although I would not advise to deactivate this in general, in your case it is needed: With this setting active FFS will first copy to a temporary file and only after this has succeded, overwrite the actual target file.

2. Deletion handling "Recycle Bin". Windows just moves files to the bin and only physically deletes them when the bin is full.

3. Deletion handling "Versioning". When the versioning directory is located on the target drive, disk space is not reduced when updating a file.