I have added the file system snapshot driver fss(4) to NetBSD-current.

It is not enabled by default in any kernel config.

To try it out:

  - Be sure you have a backup.
  - Compile and install a kernel with:
	options DIAGNOSTIC
	options DEBUG
	pseudo-device fss 4
  - Create the device nodes /dev/{r,}fss{0,1,2,3}
  - Be really sure you have a backup.
  - Use fssconfig(8) to configure a file system snapshot device.
  - Read or mount the snapshot using /dev/{r,}fss{0,1,2,3}

-- 
Juergen Hannken-Illjes - hannken@eis.cs.tu-bs.de - TU Braunschweig (Germany)