HP 345646-001 - StorageWorks NAS 2000s External Storage Server, Administration Manual

Page: 96 / 200

Shadow Copies
96 NAS 2000s Administration Guide
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.
Recovery of Files or Folders
There are three common situations that may require recovery of files or folders:
■
Accidental file deletion, the most common situation.
■
Accidental file replacement, which may occur if a user selects Save instead of Save As.
■
File corruption.
It is possible to recover from all of these scenarios by accessing shadow copies. There are
separate steps for accessing a file compared to accessing a folder.
As documented previously, the use of the snapshots are from the network and are based on
shares created on the NAS server.
On Windows 2000 SP3 clients, snapshot access is not fully functional at the share point of the
network drive. At the sharepoint, a file or folder that is deleted cannot be recovered directly. It
is recommended that end user files exist under a folder below the share point to ensure easy
recovery of their contents and that the file folders not be removed. Therefore recovery is
broken out into two categories, sharepoint and non-sharepoint. This behavior is not evident in
Windows XP or Windows 2003 clients.