The
 Previous Versions tab on the Windows desktop provides a 
straightforward, intuitive way for users to view or recover files from 
ZFS snapshots.  ZFS snapshots are read-only, 
point-in-time instances of a ZFS dataset, based on the same 
copy-on-write transactional model used throughout ZFS.  ZFS snapshots 
can be used to recover deleted files or previous versions of files and they are space efficient because unchanged data is shared between the file system and its snapshots.  Snapshots are available locally via the .zfs/snapshot directory and remotely via Previous Versions on the Windows desktop. 
  Shadow
 Copies for Shared Folders was introduced with Windows Server 2003 but 
subsequently renamed to Previous Versions with the release of Windows 
Vista and Windows Server 2008.  Windows shadow copies, or snapshots, are
 based on the Volume Snapshot Service (VSS) and, as the [Shared Folders part of the]
 name implies, are accessible to clients via SMB shares, which is good 
news when using the Solaris CIFS Service.  And the nice thing is that no
 additional configuration is required - it "just works". 
  On
 Windows clients, snapshots are accessible via the Previous Versions tab
 in Windows Explorer using the Shadow Copy client, which is available by
 default on Windows XP SP2 and later.  For Windows 2000 and pre-SP2 
Windows XP, the client software is available for download from 
Microsoft: Shadow Copies for Shared Folders Client. 
  Assuming that we already have a shared ZFS dataset, we can create ZFS snapshots and view them from a Windows client. 
   
    zfs snapshot tank/home/administrator@snap101zfs snapshot tank/home/administrator@snap102 
   
  To
 view the snapshots on Windows, map the dataset on the client then right
 click on a folder or file and select Previous Versions.  Note that 
Windows will only display previous versions of objects that differ from 
the originals.  So you may have to modify files after creating a 
snapshot in order to see previous versions of those files. 
   
  The
 screenshot above shows various snapshots in the Previous Versions 
window, created at different times.  On the left panel, the .zfs folder 
is visible, illustrating that this is a ZFS share.  The .zfs setting can
 be toggled as desired, it makes no difference when using previous 
versions.  To make the .zfs folder visible: 
   
    zfs set snapdir=visible tank/home/administrator 
   
  To hide the .zfs folder: 
   
    zfs set snapdir=hidden tank/home/administrator 
   
    
  The
 following screenshot shows the Previous Versions panel when a file has 
been selected.  In this case the user is prompted to view, copy or 
restore the file from one of the available snapshots. 
   
    
  As
 can be seen from the screenshots above, the Previous Versions window 
doesn't display snapshot names: snapshots are listed by snapshot 
creation time, sorted in time order from most recent to oldest.  There's
 nothing we can do about this, it's the way that the interface works.  
Perhaps one point of note, to avoid confusion, is that the ZFS snapshot 
creation time isnot the same as the root directory 
creation timestamp. In ZFS, all object attributes in the original 
dataset are preserved when a snapshot is taken, including the creation 
time of the root directory.  Thus the root directory creation timestamp 
is the time that the directory was created in the original dataset. 
  # ls -d% all /home/administrator         timestamp: atime         Mar 19 15:40:23 2009         timestamp: ctime         Mar 19 15:40:58 2009         timestamp: mtime         Mar 19 15:40:58 2009         timestamp: crtime         Mar 19 15:18:34 2009 
    
  # ls -d% all /home/administrator/.zfs/snapshot/snap101         timestamp: atime         Mar 19 15:40:23 2009         timestamp: ctime         Mar 19 15:40:58 2009         timestamp: mtime         Mar 19 15:40:58 2009         timestamp: crtime         Mar 19 15:18:34 2009 
  The snapshot creation time can be obtained using the zfs command as shown below.  
  # zfs get all tank/home/administrator@snap101NAME                             PROPERTY  VALUEtank/home/administrator@snap101  type      snapshottank/home/administrator@snap101  creation  Mon Mar 23 18:21 2009 
  In this example, the dataset was created on March 19th and the snapshot was created on March 23rd. 
  In
 conclusion, Shadow Copies for Shared Folders provides a straightforward
 way for users to view or recover files from ZFS snapshots.  The Windows
 desktop provides an easy to use, intuitive GUI and no configuration is 
required to use or access previous versions of files or folders. 
  REFERENCES FOR MORE INFORMATION 
  ZFS 
  ZFS Learning Center 
  Introduction to Shadow Copies of Shared Folders 
  Shadow Copies for Shared Folders Client