This article provides an overview of the snapshot and previous versions policy in place on network-attached storage (NAS) and secure network-attached storage (SecNAS) services.
Introduction
Note: In order to protect the records of the University and comply with NC Department of Cultural Resources requirements for Security Backup Files as Public Records, this service maintains 30 days of security backups. This service is not intended as an archive but provides assurance against loss of records. All retention schedule items present on the services have the same backup plan. This information is provided in compliance with UNC General Records Retention and Disposition Schedule series #7.17
ITS offers a Network Attached Storage (NAS) file service solution. Departmental storage is hosted on \\storage.unc.edu. In addition, it offers a Secure Network Attached Storage (Secure NAS) file service solution. The service is hosted on \\secnas.unc.edu. This document discusses snapshots and how you use them to recover previous versions of files and folders. the procedure is similar for both NAS and Secure NAS.
Information
Recovering Snapshots
There are two ways to recover snapshots. The easiest method is to use the “Previous Version” function native to Microsoft Windows clients. Previous Versions is a native functionality built into Microsoft Windows and Server operating systems. Previous Versions is available as a special tab under Properties for files and folders. Previous Versions allows the user to open read only past views of the file system.
Previous Versions Walkthrough
- To access previous versions, right-click on a file or folder and select Properties
- Left-click the Previous Versions tab
- Previous versions are listed by date and time stamp. Double-click the version you would like to investigate. That will open a read only view of the filesystem as it looked when the snapshot was taken.
Note: The read-only file system can be copied and restored to the working directory (or to other file systems).
A second way to recover snapshots is through direct access to the associated ~snapshots directory. This method is available to all clients. A special directory called ~snapshot is published at the root of each top level file system. This is a read only view of different states of the file system. Users can browse these directories and restore previous versions of files and folders to their regular working space. Macs and Samba clients do not have the ability to use Microsoft’s “Previous Versions” functionality. Publishing the ~snapshot directories provides an alternative restore method for these customers.
~snapshots Walkthrough
- To access the ~snapshots directory, browse to the top level of the file system
- Snapshot versions are listed by date and time stamp. Select the backup you would like to investigate. This will open a read only view of the filesystem as it looked when the snapshot was taken
- Traverse the directory until you locate the file(s) you would like to recover. The read only file(s) can be copied and restored to the working directory (or to other file systems).
Schedule
Snapshots are performed on the following schedule:
Today – 8am
Today – Noon
Today – 4pm
Today – 8pm
Today – Midnight
Yesterday – 8am
Yesterday – Noon
Yesterday – 4pm
Yesterday – 8pm
Yesterday – Midnight
Plus the 5 most recent weekly Sunday@Midnight snapshots
This strategy gives users the ability to go back a maximum of 30 days to restore data.