Network Servers: Everything You Wanted to Know but Were Afraid to Ask
service capabilities? Also, sometimes if a server fails, other existing servers
might temporarily meet some of its needs. For example, in a Windows network,
if a domain controller fails, you can have other domain controllers to provide
this necessary functionality for the network as a whole. Or you might have
redundant printer queues defined on another server, ready to be made available
if the primary print server fails.
How do you plan to back up the server? Do you plan to have a tape drive on
the server itself, or do you plan to back it up over the network to some other
server's backup device? Do you plan to make backups while the server is being
used, or overnight when it's not being used? These are important questions
to answer, because if you host the backup device on the server, you also need
to have backup software on the server. If you plan to back up a server while
it's being used, you need a fast backup system connected to a fast server bus
to minimize the impact to the users during the day. If you plan to back up a
server over a network connection, you need a network connection fast enough
to handle the amount of data on the server. Think carefully about your backup
plans when specifying a server.
How could the demands placed on the server change over time? Is the company
aggressively hiring more employees, so that the server might need to support
twice as many users a year from now and four times as many users two years
from now? Make sure you understand the company's overall plans and factor
them into your assessment of server needs. Also, even in companies where
the number of users is relatively static, the amount of storage required by each
user will still grow rapidly. A rule of thumb is to estimate that current storage
requirements double every 18 months, everything else being equal. If you have
historical data for how much storage users consume, this data can help you
estimate your system's requirements even more accurately. (And don't forget
to anticipate any new network services that could more rapidly increase your
Does the new server need to work with any existing hardware? If you need to
reuse a network backup device, for instance, you should make sure that the
new server can properly support it (and vice versa).
How much physical room do you have available to house the server? Are you
compelled by space requirements to go with the smallest server possible?
Once you answer these questions and any others that might crop up, you're ready
to start looking at different servers that can meet the needs you defined.
Selecting the Server
Aside from choosing the types of equipment you need for a server, you must remember
three basic prerequisites that all your server purchases should meet: compatibility,
compatibility, and compatibility. If your NOS starts displaying error messages on