Networking: A Beginner's Guide
Your tape backup drive fails and cannot be repaired for one to two weeks.
While this doesn't cause a loss of data in and of itself, it certainly increases
your exposure to such an event.
You should plan how you would respond to these and any other possible failures.
If the motherboard in your main server fails, you may want to move its drives to a
compatible computer temporarily. To address disk failure, you should design a plan
under which you can rebuild the disk array and restore data from your backups as
rapidly as possible. Regarding your tape backup drive, you will likely want to find out
how quickly you can acquire an equivalent drive or whether the maker of the tape drive
can provide reconditioned replacement drives quickly in exchange for your failed drive.
For all of these failures, you will also want to consider the cost of keeping spare
parts, or even entire backup servers, available so that you can restore operations as
rapidly as possible. You should consider and investigate all of the following types of
Should you carry a maintenance contract? If so, make sure you thoroughly
understand its guarantees and procedures.
Should you stock certain types of parts on hand so that they are readily
available in case of failure?
Are other computers available that might work as a short-term replacement for
a key server? What about noncomputer components that are important, such
as routers, hubs, and switches?
If you need to take temporary measures, are the affected employees trained to
do their jobs with the replacement, or with no system at all, if necessary? For
example, if a restaurant's electronic systems are down, can the restaurant (and
the food servers, kitchen staff, cashiers, and so on) still operate the business
manually until the system is repaired?
Should you maintain a cold or hot recovery site? A "cold" recovery site is
a facility maintained by your company and near the protected data center.
The cold site has all of the power, air conditioning, and other facility features
needed to host your site should the data center experience some disaster. A
"hot" site is the same as a cold site, except that it also has all of the necessary
computer equipment and software to duplicate the processing of the data
center. Hot sites usually synchronize their data on a real-time basis with the
main processing center, so that they can literally take over the work of the main
site in seconds. Companies with very sensitive, mission-critical data operations
often maintain cold or hot recovery sites.
The process of considering possible problems, such as disasters or failures of key
pieces of equipment, and then making plans for handling them is certainly the meat of
disaster recovery planning. However, your written plan should also discuss or address
other issues, which are covered in the following sections.