Autodir supports backup program launching when a virtual directory is removed after a period of inactivity. Removal of virtual directory is itself is an assurance that no other application can access the content and modify it.
Like there is wait duration for expiring virtual directory, for backup also Autodir waits some more time, after virtual directory expiration, for starting backup. This time period can be configured through command line option to Autodir.
By design, backup programs are expected to operate on real directory but not on virtual directory. If backup program try to access virtual directory Autodir assumes some regular application is in need of that directory and backup program is killed even if the virtual directory accessing process is backup program itself.
A separate backup process for each real directory is used. The backup program can be given arguments of real directory on which to operate.
Backup support is independent of any particular module being used. It is applicable to all modules with Autodir.
Backup programs should never access virtual directory or virtual base directory.
Backup feature is not much useful if virtual directories are accessed all the time by applications.