Managing Data Center
Chapter 11.
Labeling and Signage
Choosing a Numbering Scheme
• It is necessary to number each cabinet location in a server
environment for several reasons.
• At the most basic level, numbering creates a common
frame-of-reference for navigating and working in the space.
Data Center servers and infrastructure can be assigned
specific locations.
• Labeling isn't useful only for knowing where to place
servers and networking devices; it is equally important to
have defined destinations for structured cabling and
electrical conduits.
• a numbering scheme lends itself to creating a database of
Data Center equipment that includes location information.
Choosing a Numbering Scheme (Cont)
• the most common Data Center numbering scheme involves laying a
virtual grid over the Data Center and establishing coordinates for
each floor tile location. plotting coordinates along X and Y axes.
Letters proceed in sequence on one Data Center wall, while
numbers proceed in sequence along another wall that is
perpendicular to the first.
Choosing a Numbering Scheme (Cont)
• Grid numbers are typically printed high on each Data Center wall,
just below the ceiling line. This is intended to make the information
visible throughout the server environment. In practice, however,
these numbers can be hard to see when standing in the middle of a
server row with industry-standard server cabinets. Some companies
also print the grid coordinates on floor panels, which is effective as
long as tiles are returned to their correct locations after being lifted
to access the under-floor
Choosing a Numbering Scheme (Cont)
• An advantage of the grid system is that it is based upon
physical coordinates within the Data Center and not
limited solely to cabinet locations. The grid therefore
can also be used to indicate the locations of major
infrastructure on the Data Center floor, not just
servers. Recording specific locations on the grid for air
handlers, power distribution units, sprinkler heads,
cylinders containing fire suppressant, or structural
columns is also useful.
• EX: for example, air handlers are located at grid
locations 33A, 24U, 15A, and 7U
Choosing a Numbering Scheme (Cont)
• Another approach is the labeling of server rows
themselves in sequence, Row 1 would contain
cabinets 1A, 1B, 1C, and so on; Row 2 would
contain cabinets 2A, 2B, 2C, and so on.
• people find this numbering system familiar and
therefore easier to work within than the grid. Its
only shortcoming compared to the grid is that it
only creates location information for devices
located within server rows, and can't be
expanded to air handlers and other major
infrastructure components
• No matter what numbering system you use, large objects such as
disk libraries inevitably overlap onto multiple coordinates. When
determining the location information of a large object, don't list
multiple locations. Doing so can be confusing. Instead, choose one
reference point and be consistent. Establish all location coordinates
based upon the center or upper left corner of the device, for
example.
Recommended Labeling Practices
• What to label? label everything: Structured cabling, Power
receptacles and circuit panels, Cabinets, Raised floor tiles,
Individual servers and networking devices, Entire server
rows, Major infrastructure components.
• How to label? there are several options: Printing on address
labels, Using pre-printed stickers, Ordering engraved signs,
Writing on masking tape with a marking pen.
• Notes:
– employ large lettering with an easy-to-read font and choose a
consistent format.
– Always place labels in a prominent location—you want the
information that they contain to be easily noticed by Data
Center users or support staff. Put labels at eye level when
possible or at least somewhere that has an unobstructed line of
sight. EX: Floor tile surfaces are excellent for providing
information
Recommended Labeling Practices
(Cont.)
• Cable Runs
– The structured cabling should include labeling that
contains what type of media is in use (i.e., 50 mm
multimode or Category 6 copper) and the cabinet
locations that a cable run connects from and to (i.e.,
from cabinet 1A to cabinet 1D).
– Place it everywhere that the structured cabling
terminates—at the main networking row, in network
substations, and at server cabinet locations.
Specifically, label the fiber housings, patch panels, and
multimedia boxes where Data Center users patch in to
the structured cabling infrastructure.
• This figure illustrates typical labeling on a fiber
housing and copper patch panel within a
networking substation. The labeling indicates
what type of fiber terminates there and lists
the from/to locations of the structured cabling
Recommended Labeling Practices
(Cont.)
• Electrical Conduits
– power receptacles are labeled to help with
troubleshooting. In the event that a power malfunction
occurs or a circuit breaker trips, the facilities or Data
Center support staff needs the information to trace a
problem from an electrical receptacle to a circuit panel and
back to the source power distribution unit. Labeling
circuits also enables power to be managed so that Data
Center cabinet locations are provided with electricity from
different sources consistently.
– Label electrical receptacles, circuit breaker panels, and
power distribution units. Include circuit information,
voltage and amperage, the type of electrical receptacle,
and where in the Data Center the conduit terminates
Recommended Labeling Practices
(Cont.)
This figure illustrates suitable
labeling on a Data Center
electrical receptacle. A power
receptacle, shown in both NEMA
5-20R and L6-30R configurations,
is fed by circuits 2 and 4 from
PDU1 panel A.
•
• This table shows a typical power
schedule format that can be
found in a single electrical panel,
either as a standalone panel at
the end of a Data Center row or
one of several panels within a
larger power distribution unit.
Whenever power is changed in your server environment, whether it is running entirely new
electrical conduits or simply modifying what's already in place, make sure all labeling and
power schedules are updated when the work is done.
Recommended Labeling Practices
(Cont.)
• Cabinet Locations
– At a minimum, show what electrical circuits are
powering each cabinet location and, by extension,
the devices within them. Atop the corresponding
raised floor panel and server cabinet, duplicate
the data that's printed on the circuit panels and
electrical receptacles. If power terminates above
each cabinet location, circuit information should
be printed on the overhead raceway near the
appropriate receptacle.
•
This picture shows electrical
circuit information posted on the
bottom rail of a server cabinet as
well as on the floor tile below it. •
One power strip in this server
cabinet is powered by PDU9
panel L, circuits 6 and 8; the
other is powered by PDU8 panel
E, circuits 6 and 8. The cabinet is
at Row 57, cabinet I.
it can be difficult to see over a server row
to tell what specific location you are at
within a Data Center. To mitigate this, put
location information on each cabinet.
Unless your Data Center is static, with
minimal changes to the equipment that
it houses, your server cabinets are likely
to be relocated periodically. Be diligent
about keeping their labeling up to date.
Outdated location labeling can be
confusing, and obsolete electrical
information can lead to serious mistakes.
Recommended Labeling Practices
(Cont.)
• Servers and Networking Devices
– Assign distinct names to Data Center servers and
networking devices. Clearly label them on both their front
and back sides, including any related peripherals, as part of
the machine's installation process.
– Some prefer very straightforward names, such as
PRODSERV1, DEVBOX, EMAILSERV, and so on. Others
prefer more fanciful ones, drawing names from television
characters (CAPTAIN KIRK, MR. SPOCK, DR. MCCOY),
everyday objects (BAT, BALL, GLOVE), or anything else that
can be considered a recognizable group (VANILLA,
STRAWBERRY, CHOCOLATE). Any of these patterns work
fine in the Data Center, just as long as servers and other
items are consistently named and thoroughly labeled.
• These figures show the front and back of a fully loaded
cabinet, containing properly labeled servers.
Recommended Labeling Practices
(Cont.)
• Server Rows
– One of the first challenges that
new Data Center users often face is
physically finding a particular
server within the room. This can be
especially challenging in a server
environment that is very large or
whose equipment isn't arranged in
any particular manner. To make it
easier to find specific servers as
well as promote the overall
organization of the room, post
signs that show row numbers and
which group each is assigned to.
– Also post an alphabetized list of
equipment at the end of each Data
Center row, indicating which
cabinet position each device is in.
Recommended Labeling Practices
(Cont.)
• Piping
– Any water-bearing pipe in a
Data Center presents a
potential risk for leaking.
Clearly mark such piping,
especially any segments that
are in high-traffic areas and
therefore the most vulnerable
to accidental damage. Such
labeling is not only intended
to make Data Center users
more cautious around the
piping, but also, in the event
that water does leak in the
server environment, it
narrows down what piping
needs to be examined as a
possible source of the liquid.
– Label cylinders that contain
fire suppressant, as well.
Essential Signage
• Fire Alarm Instructions
– a typical Data Center can possess up to three
automated elements for detecting and fighting a fire
(a smoke detection system, water-based sprinklers,
and gaseous fire suppression). All three systems
feature alarm mechanisms to indicate when they have
been activated. These alarms, all wall-mounted in
multiple locations within the server environment,
should also include explanatory signage that informs
Data Center users of their function and what to do in
the event that they activate.
Essential Signage (Cont.)
• From left to right, an alarm bell indicates that smoke has been
detected in the Data Center, a white strobe light shows that a
building fire alarm has been activated, and an amber strobe light
signifies that the countdown has begun to activate the Data
Center's gaseous fire suppression system.
• These placards, located next to each alarm station, are typically
supplemented by large signs on the Data Center door informing
users to leave the room in the event that any fire alarms engage.
Essential Signage (Cont.)
• Fire Suppression System
Instructions
– Unlike other firefighting
mechanisms, a Data Center's
gaseous fire suppression system
features manual controls within
the room that enable a person
either to pause the system's
automatic countdown to
activation or to cause an
immediate discharge.
– Signage must be placed at the
fire suppression controls that
explains how someone can
correctly operate them.
Essential Signage (Cont.)
As important as your Data Center's
overall fire suppression system is, if a
small fire breaks out, it is likely that the
first response of anyone in the room will
be to look for a portable fire extinguisher.
Make their task easier by providing
signage that makes the extinguishers
easier to find.
This figure shows a wall-mounted fire
extinguisher, with an overhead placard
that helps call attention to it. The placard
is placed just below the Data Center
ceiling and protrudes outward, to
increase its visibility
Essential Signage (Cont.)
• Emergency Power Off
(EPO) Instructions
– This system enable someone
to shut down all Data Center
servers and networking
devices—literally at the
touch of a button—it is vital
that they be clearly and
thoroughly labeled to reduce
the chance of an accidental
activation.
– Signage must explain what
the EPO controls do, how
they can be activated, and
what their area of effect is
Essential Signage (Cont.)
• Monitoring Lights
– Assuming you include these monitoring lights as part of
your server environment's standby electrical
infrastructure, be sure to include signage that explains
their purpose and whom Data Center users should contact
in the event that they come on.
– The red light (left) activates when the Data Center's
electrical load is provided by UPS and the blue light (right)
activates when it is provided by generator. (The phone
number to call is intentionally obscured in this figure.)
Essential Signage (Cont.)
• Emergency Contacts
– Even if your Data Center doesn't have monitoring
lights, post lists in the room that inform room
occupants whom to contact if a power outage or
other infrastructure-related incident occurs. This can
be just the phone number for your company's
operations command center or a detailed list of
people who support the server environment and how
to reach them.