Network Disaster Recovery
Formally planning with the key areas of your company's business (for example,
manufacturing, customer service, and sales) considerations surrounding different
types of computer-related disasters or serious problems
Assuring customers of the firm that the firm's data operations are safe from
Identifying these needs will not only give you a clear vision of what the plan must
address, but also which other people from the different parts of the company should be
involved in the planning process.
Considering Disaster Scenarios
You should start your planning process by considering different possible disaster
scenarios. For example, consider the following disasters:
A fire in your server room--or somewhere else in the building--destroys
computers and tapes.
Flooding destroys computers and backup batteries low enough to the server
room floor to be affected. Remember that floods may be caused by something
within the building itself, such as a bad water leak in a nearby room or a fire
that activates the fire sprinklers.
An electrical problem of some kind causes power to fail.
Some problem causes total loss of connectivity to the outside world. For
example, a critical wide area network (WAN) or Internet link may go down.
A structural building failure of some kind affects the network or its servers.
Any of the preceding problems affects computers elsewhere in the building
that are critical to the company's operations. For example, such an event may
happen in the manufacturing areas, in the customer service center, or in the
telephone system closet or room.
While none of these events is very likely, it is still important to consider them all.
The whole point of disaster recovery planning is to prevent or minimize serious losses,
and the process is much less useful if you consider only those disasters that you think
are the most likely.
After considering disasters such as those mentioned, you should next consider serious
failures that could also affect the operations of the network. Here are some examples:
The motherboard in your main server fails, and the vendor cannot get a
replacement to you for three or more days.
Disks in one of your servers fail in such a way that data is lost. If you are
running some kind of redundant array of independent disks (RAID) scheme
(discussed in Chapter 13), plan for failures that are worse than the RAID system
can protect. For example, if you use RAID 1 mirrored drives, plan for both sides
of the mirror to fail in the same time frame. If you are using RAID 5, plan for
any two drives failing at the same time.