Redundancy is good all around computer networks

The word redundant is usually associated as useless or wasteful. But in the world of Information Technology where so much depends on the integrity of your data, redundancy is a very good thing!

Redundancy at the root: The Server

One of the fundamental corollaries of data security is redundancy. Anything that is 'Mission-critical' become an Achilles Heel; its failure causes severe difficulty whether only in the form of the interruption of work or more terribly in the form of lost data. For small and medium-sized businesses, a server is necessarily mission-critical. The only way around that fact is to purchase and maintain multiple servers that are capable of replicating both data and functionality. This is usually cost-prohibitive for small and medium-sized businesses.

Redundancy for servers is primarily implemented through a multi-layered backup scheme. Allora's preference is to have all of its clients use RAID-1 mirrored hard drives in their servers. At any given time in a RAID-1 equipped server, there are two independent copies of all server operating system files and company data files available to the server itself and to network users respectively. Therefore, if one of the hard drives in the server fails, the server remains functional and most users on the network will not even notice a problem. The daily operations of the office will not be interrupted while a replacement drive is obtained and the failed drive is replaced. In the same vein, redundant internal power supplies as well as a UPS battery-powered backup are important considerations as well. The idea is that if the server has to be mission-critical, as many of its various primary components as possible should be made redundant and protected.

In addition to using mirrored hard drives, server system files and data can and should be protected via secondary backup measures as well. Backups can be made automatically using scheduled routines to copy important files to other locations, such as to a tape drive or a secure shared directory on another computer. Data can also be backed up manually to portable media such as memory sticks or CD-R/CD-RW discs or to other network shares. Furthermore, at least one of these forms of backup should be periodically moved to and stored in a remote location in case of a major catastrophe such as a building fire at the main location. By using combinations of all of these options, there is redundancy in the backups and the chances that important data will survive are drastically improved.

Further Redundancy: Workstations

Once these backup routines have been established, Allora recommends implementing additional layers of redundancy at the workstation level. The use of Roaming User Profiles, remapped 'My Documents' folders, and standardization of workstations all work together to minimize the risk of data loss or disruption of work due to a hardware failure in a user's workstation. These policies also make the individual workstation computers fully expendable and therefore not in and of themselves mission-critical.

Roaming User Profiles store most personal user account configuration information on the server. Once a System Administrator or the actual user if so allowed has customized his or her user account configuration, those settings are accessible to any computer in the local domain that the user needs to use. When the user logs on, personal E-mail accounts, documents, bookmarks or 'Favorites,' and even desktop pictures are automatically loaded onto that computer, even if the user has never logged onto it before.

By default, a user's My Documents folder is created on the local hard drive of a computer when the user logs on to it for the first time. When the user with a Roaming User Profile finishes work and logs off of that computer, the local My Documents folder is copied in its entirety to the profile directory on the server corresponding to the user's account. This has a couple of limitations or drawbacks. If the user has a very large amount of data in his or her My Documents folder, it can take a long time to copy them all back and forth across the network every time the user logs on or off. Secondly, if the computer crashes in the meantime, all of the data that is either new or modified since the last time the user logged off is also lost.

The solution to this My Documents issue is to include a privately shared data directory on the server for each and every user and within that directory create a new 'My Documents' folder. The default My Documents folder found on the user's desktop is actually just a shortcut and it can be easily remapped to the new folder on the server. Once all of the user's personal files are moved to the new My Documents folder on the server, the files only move across the network when they are opened by the user and then saved back again. They are also automatically protected and backed up as part of the server's own backup routines.

Enhanced Redundancy: Standardization

The final component of user-level redundancy in an office environment is to standardize workstations as much as possible. Ideally, if every workstation is identical, setup and installation are minimized and simplified as much as possible. Even with Roaming User Profiles, there are Local Settings that are necessarily unique to each computer, but if every computer is exactly the same, those local settings are minimized and are relatively insignificant. Furthermore, it is then easier for the network Administrator to track and manage workstation components such as applications, drivers, or spare parts. Individual workstations become easily replaced modules in your office network and users can move to other existing or newly installed computers without any reconfiguration or modification of either the computer or the user account settings.

When workstations are not standardized or when they contain unique software and/or hardware, they become harder to manage or replace. Just to start with, the differences must be tracked and recorded for reference. Next, the differences will impact routine maintenance and service. Microsoft Office, for example, requires access to its original installation files during the installation of program updates and security patches. This makes it imperative to keep that software stored in a segregated, organized, and readily available location, something that also requires considerable administrative effort.

Another standardization issue case comes from the interaction of Roaming User Profiles with computers that are running different operating systems such as Windows 7 Professional and Windows XP Professional. Unfortunately, Microsoft felt a need not only to change the appearance of the user interface in Windows XP, but also to move the location of many program shortcuts in the Start Menu and Programs list. Consequently, roaming users who move back and forth between these operating systems will often encounter invalid program shortcuts or icons.

Of all of these policies, workstation standardization is by far the most difficult to implement. Computers are often added or replaced one or two at a time in an office network and given the nature of progress and development in information technology, the choices of Operating Systems, programs, and hardware are continuously changing. Nonetheless, it is an ideal or goal for which we should strive because of the savings in system maintenance and administration that it provides. And because redundancy is good!