Caution
Chapter 9 Introduction to the Server
373
blade server
a powerful server
that is extremely
thin. It is designed
to be mounted in
a small space with
other blade servers.
hot-swap
technology
a technology that
allows a component
to be removed or
installed while the
system is running.
Do not open a CRT (monitor) while wearing an antistatic wrist strap, even if the CRT is
unplugged. CRT screens can hold a high voltage charge for long periods of time after they
have been disconnected from electrical power.
The major components of a server are similar to a typical PC. In fact, you
can use a typical PC as a server for a small network. A network server can
be as simple as a typical PC or as complex as a piece of equipment designed
exclusively for networks. Some server models with multiple CPUs, large amounts
of RAM, and vast amounts of storage space can be thought of as a “small”
mainframe rather than as a PC. There are many server designs available. As part
of your study of network servers, it is highly advisable to check the IBM, Sun
Microsystems, HP, and Dell Web sites to see the available designs. This section
looks at the following components: case, hot-swap components, power supply,
motherboard, BIOS, and CPU.
Case
Server case styles vary greatly. Some are similar to desktop models. Some are
designed to be mounted into a rack like the server in Figure 9-2.
Large enterprise servers are actually a group of individual servers mounted
in a rack system or cabinet, Figure 9-3. The group of servers acts as one unit that
has multiple CPUs and a large amount of system resources, such as hard disk
drive storage and RAM.
A blade server derives its name from its size and shape. It is extremely thin
compared to other servers and fi ts into a rack, Figure 9-4. Blade servers are
especially designed to allow a large number of servers to be mounted in a small
space. Blade servers are not to be confused with thin servers. A blade server can
contain more than one processor and be quite powerful. They are often selected
for applications where there is a requirement for many servers to perform the
same or similar function. For example, they may be used in a large Web service
facility or a fi le server farm.
Hot-Swap Components
Servers are generally designed to provide continuous service with minimal
interruptions and data loss. The main feature that most servers use to provide
this continuous service is hot-swap technology. Hot-swap technology allows a
component to be removed or installed while the system is running. There is no
need to power down the system while replacing or adding major components.
Some common hot-swap components are hard disk drives, memory modules
(RAM), CPUs, and power supplies.
Never assume a component is hot-swappable. Always check the system
manual before removing any component while the system is powered on.
Figure 9-2.
The ProLiant DL740
can be mounted into
a rack. (Hewlett-
Packard Company)