Storage Basics: Backup Strategies, Part 2 Page 2
The LAN-Free Backup Solution
A LAN-free backup solution allows you to use a storage area network (SAN) to create a shared, centralized backup and recovery point. It offers the management capabilities of a centralized backup solution while at the same time also delivering the performance of distributed backup solutions. LAN-free backups take the backup traffic off of the LAN by using dedicated links to network servers with centralized storage devices.
Each server maintaining data that must be backed up requires a Fibre Channel adapter that connects to a Fibre Channel hub or switch. The hub or switch is connected to a tape library or disk array.
In this configuration, a single server, or server cluster, can act as the central backup point for all servers on the network. All backup traffic travels through dedicated high-speed links, reducing the load on the regular LAN links and all but eliminating the limitations of the backup window.
The Server-Free Backup Solution
LAN-free backups increase backup speeds and centralize management, but what if it were possible to take backups one step further and transfer backup data directly from disk to tape without using a server? This option is known as a server-free backup.
When we talk about a server-free backup, we are referring to a process where the backup data path does not go through a server. While a server is needed to control the overall process and maintain the backup software, data is passed between disk and backup library without requiring a server’s CPU. This frees server resources to be used elsewhere on the production LAN.
There are several advantages to implementing a server-free backup solution, including offloading traffic from the LAN, reducing the load on server system resources, and high-speed data transfer. As with most areas of technology, though, there are also a few drawbacks. A server-free backup solution is more costly and complex to design and manage, and when something goes wrong, they can be very difficult to troubleshoot.