Mark a snapshot being deleted before actual deletion

[Mauro]

The deletion of a snapshot, performed by the automatic and/or smart removal, may take a while, especially if the snapshot contains many files and/or if it's on a slow NAS.
Also, the deletion process may be interrupted and restarted at a later time (think about a system shutdown, for instance, while deletion is in progress, or a broken connection in case of a remote backup without "deletion in the background" option).
This means that a snapshot may remain "partial" if its deletion was started but never finished. If you don't know about this condition, you may think it's a complete snapshot while it isn't and you may lose data if you try to restore files from it.

This improvement is to "mark" a snapshot being deleted just before deletion starts, for instance by renaming its folder to something like <timestamp>_deleting or deleting_<timestamp> or such. This would make explicit that the snapshot is likely to be partial because it is being deleted.
The most critical part is to make BIT recognize a partially deleted "marked" folder to be deleted again if the previous deletion was interrupted (mainly because it has a different naming convention).

[Germar (germar)]

You're right. Would be good to add this. Maybe we can change the remote smart remove process to choose and delete those 'marked' snapshots, too.