The category of network backups contains a number of possibilities. Typically, it refers to designating one file server as a backup server, onto which backups from other servers (and potentially workstations) are stored. This server should be configured with a great deal of fault tolerance in its design (typically using RAID arrays for storage) and, depending on your network’s size and budget constraints, have a second server that serves as a backup server for the backup server (or at least have a separate backup strategy utilizing fixed media or tape). If your network spans multiple locations, you might want to consider building a backup server at each location and mirroring or synchronizing the contents of the servers to each other as an option for both fault tolerance and a method of maintaining off-site backups. In the case of particularly large and active networks, you might also find that using storage area network technology plays a very active role in your backup consideration (although discussion of such technology is beyond the scope of this series).
A backup server can function as simply a server hosting a share point to be used for storing backups or can be implemented using a client-server backup tool. In the first case, backup software running on the servers (or workstations) using the backup server simply stores files on it, accessing it like any other mounted disk or share point. In the second, the backup service running on the backup server will actively query and interact with a backup client tool installed on the server or workstation to be backed up. This removes some of the overhead of managing the backup process from the server being backed up and it enables centralized management of the backup process for multiple servers and/or workstations (as discussed in Part 1 of this series).
If you are in a small or medium-sized organization, you might be able to use a network attached storage device, such as a Snap drive, as a network storage solution instead of a full-blown server. These devices, which are essentially a hard drive with a very basic operating system that enables them to host share points using varying protocols, often cost significantly less than implementing a full server. The trade-off is that they cannot offer anything other than basic network storage space as a traditional server can, although if you are simply looking for a place to store backups, this might not be a concern. These devices typically cannot be formatted as a part of a RAID array.
Finally, network storage can consist of using an outside company for storage over a secure Internet connection. This is often appealing if your company or school is big enough to have high-speed Internet connectivity and require off-site reliable backups, but doesn’t include the resources for maintaining adequate backups on its own. Several companies specialize in such services, and many ISPs can also simply provide storage space. This option solves issues such as maintaining off-site or multisite backups but opens some security concerns to be worked out with the company you choose. It also offers you the option of maintaining your own onsite backup server and using their services for a second tier backup.
Whichever method you select for network backup, remember that you are likely to be transferring extreme amounts of data over your network as it is backed up. You will want to automate the backup processes so they run when network use is minimal. In some cases, complete and incremental backups might be too much for your network to handle even on an overnight basis, so you might need to take this into consideration. In such cases, you will likely need to plan your backup strategy using mostly differential backups.