vfs_shadow_copy — Make a Samba share read only for a specified time period
vfs objects = shadow_copy
This VFS module is part of the samba(7) suite.
The vfs_shadow_copy VFS module functionality
	that is similar to Microsoft Shadow Copy services. When setup properly,
	this module allows Microsoft Shadow Copy clients to browse
	"shadow copies" on Samba shares.
	
This module is stackable.
vfs_shadow_copy relies on a filesystem
	snapshot implementation. Many common filesystems have native
	support for this.
	
Filesystem snapshots must be mounted on
	specially named directories in order to be recognized by
	vfs_shadow_copy. The snapshot mount points must
	be immediate children of a the directory being shared.
The snapshot naming convention is @GMT-YYYY.MM.DD-hh.mm.ss, where:
YYYY is the 4 digit year
MM is the 2 digit month
DD is the 2 digit day
hh is the 2 digit hour
mm is the 2 digit minute
ss is the 2 digit second.
The vfs_shadow_copy snapshot naming convention can be produced with the following
	date(1) command:
	
TZ=GMT date +@GMT-%Y.%m.%d-%H.%M.%S
This is not a backup, archival, or version control solution.
With Samba or Windows servers,
	vfs_shadow_copy is designed to be an end-user
	tool only. It does not replace or enhance your backup and
	archival solutions and should in no way be considered as
	such. Additionally, if you need version control, implement a
	version control system.