Tandberg Data NAS Hardware Viking FS-1500 - Manual (Page 55)

Tandberg Data Shadow Copy Service
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4-17 Tandberg Viking Series Storage Server Administration Manual
4.7.2. NFS Access to Shadow Copies
UNIX users can independently access previous versions of files stored on
NFS shares via the NFS client; no additional software is required. Server for
NFS exposes each of a share's available shadow copies as a pseudo-
subdirectory of the share. Each of these pseudo-subdirectories is displayed
in exactly the same way as a regular subdirectory is displayed.
The name of each pseudo-subdirectory reflects the creation time of the
shadow copy, using the [email protected]:MM:SS. Note that,
to prevent common tools from needlessly enumerating the pseudo-
subdirectories, the name of each pseudo-subdirectory begins with the dot
character, thus rendering it hidden.
The following example shows an NFS share named “NFSShare” with three
shadow copies, taken on April 27, 28, and 29 of 2003 at 4 a.m.
NFSShare
@ GMT-2003.04.27-04:00:00
@ GMT-2003.04.28-04:00:00
@ GMT-2003.04.29-04:00:00
Access to NFS shadow copy pseudo-subdirectories is governed by normal
access-control mechanisms using the permissions stored in the file system.
Users can access only those shadow copies to which they have read access
at the time the shadow copy is taken. To prevent users from modifying
shadow copies, all pseudo-subdirectories are marked read-only, regardless
of the user's ownership or access rights, or the permissions set on the
original files.
Server for NFS periodically polls the system for the arrival or removal of
shadow copies and updates the root directory view accordingly. Clients then
capture the updated view the next time they issue a directory read on the
root of the share.