What does files in Backlog mean?
In some cases, Yadis cannot copy the file when the user modifies or creates it. This can be because the backup drive is not available. If this happens Yadis creates a backlog file in order to remember which files still need to be copied once the backup drive becomes available again.
If this happens, Yadis will automatically attempt to make a backup at that time and on succes it will remove the backlog file.
If, for some reason, a file cannot be copied, you can find the reason for this in the backlog info section of your task.
In order to see this information, select yourtask in the task list, press the info button and select the "Task Info > Backlog" section. Here you see a list of files not yet backupped. Click on a file to get the reason why it could not be backupped in the lower section of the screen.