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Hardware Today: Sensoring the Server
By Drew Robb
Servers have long had certain types of environmental monitoring
built into them. Administrators can configure management
software to detect when the fan dies or the temperature
soars and issue alerts accordingly. These days, however,
that isn't enough. Why wait until a server starts melting
before discovering a climate control issue?
The bottom line is you have to monitor the entire server
Environmental sensors are not important at all until suddenly
they become very important.
And that's where environmental sensors come in. With features
like TCP/IP-based remote monitoring, abnormal status notification
via e-mail messaging or SMS, and SNMP support, they provide
an additional means of safeguarding sensitive resources.
"Environmental sensors are not important at all until
suddenly they become very important," said Jon Collins,
principal analyst for Quocirca, a U.K.-based industry
analyst firm. "Many IT managers view them as a relatively
cheap addition to the server room compared to the cost
Units are mounted on a wall or equipment rack, or placed
on a shelf. They can be centrally monitored from a workstation,
over the Internet using a Web interface, or wirelessly
using a PDA. The devices come with their own specialized
monitoring and management software, but since they use
SNMP they can also be incorporated into other network
management software as another node to monitor. Generally,
the base unit of an environmental sensor can be attached
to additional sensors as required.
Making Sense of Environmental Sensors
Sensors should monitor for the following:
Temperature: It is not good enough simply to nail a thermostat
to the wall. Since the temperature can vary drastically
around different pieces of equipment, consider placing
separate temperature probes on individual racks or critical
devices. That way, problems with a broken fan or air conditioning
failure will show up quickly. For best results, stick
with microprocessor-based temperature sensors. A CAT 5
cable, for example, ensures accuracy does not diminish
due to cabling factors. Avoid sensors that demand calibration
to maintain the correctness of readings.
Humidity: If humidity is too high, it can lead to corrosion;
if it's too low, you have static electricity problems.
Airflow: While the building engineering team may be alerted
when the air conditioner trips a breaker, IT managers
want to be sure the air is actually flowing at a high
enough velocity down through the racks. Airflow hovering
around the ceiling grille isn't good enough. The air must
get down to the floor-level servers in the path of the
air stream where the status and amount of the flowing
air can be properly monitored.
Water: Sensors should be capable of detecting the presence
of water so remedial action can be taken before it shorts
out equipment. Water detectors should be microprocessor
based, capable of detecting distilled water, and encased
in epoxy so the device can function while submerged.
Voltage: Voltage sensors detect the presence or the absence
of line voltage. They can prove useful in identifying
the frequency of brown outs for measuring uninterruptable
power supplies and service provider performance. The best
voltage sensors come with a measurement range between
50v to 250v.
Dry Contact: Dry contact sensors detect broken surfaces,
such as when someone opens a door or breaks a window.
As soon as someone opens the door to the data center,
a trap or page is transmitted informing the admin that
someone has opened the door to a secure area.
Sensors should have, at a minimum, the following functionality:
Notification: The IS organization should be able to set
temperature thresholds for alerts. For example, if the
air conditioner breaks, the temperature sensor should
immediately tell the probe to page an administrator. Probes
should be able to send out alarms via e-mail, SMS, or
Interfacing: Environmental probes should be able to interface
with the major SNMP-based network management systems,
such as HP OpenView, IBM Tivoli, and CA Unicenter.
Camera: Cameras add an extra layer of security, as they
enable staff members to see who is in the server room
or remote server closets. They also provide the IS organization
with a record of who was in the various rooms and what
they did there. Cameras are also helpful for remote offices
without a local IT rep. When troublshooting issues, for
example, someone can walk around the server room with
a camera while on the phone with the main data center.
Today, some probes come with cameras that have adjustable
mounted lenses with widescreen pan and scan features.
Be aware, though, that cameras can add significantly to
the price tag. We recommend adding one only if you are
fairly certain you willuse the features.
Several companies sell environmental probes, including
undisputed market leader NetBotz, which boasts of 3,000
customers in more than 30 countries. Although there are
no clear-cut analyst numbers for the size of this market,
NetBotz did a conservative calculation during its last
round of financing.
With the price point on the latest crop of devices, one
set of probes is unlikely to cost more than one minor
"We estimate the market potential at $6 [billion]
to $9 billion in terms of the number of racks and server
rooms out there," said Mitch Medford, CTO of NetBotz.
Medford said recent upgrades to the NetBotz product line
are wireless technology, embedded Linux for added security,
and the capability to mix and match features, such as
adding more cameras to the base unit. Units start at around
$1,000 for small server rooms (10 feet by 10 feet) and
cost as much as $3,000 for larger spaces. As extra sensors
or cameras are ordered, the price increases.
But the popularity of sensors is attracting competition.
Phonetics, RLE Technologies, and Javica, are three companies
creeping in on NetBotz' turf. Each offers decent equipment
at a lower price, albeit without the bells and whistles
or end-to-end integration that NetBotz offers. For many
server rooms, these units will do the job. Prices for
a Javica BitSight unit, for example, start at around $400.
"While facilities personnel will provide the necessary
level of BTUs to cool the room, they won't necessarily
know or care whether you have a hot spot next to a particular
server rack," said Marc Bilodeau, CTO of Javica.
"This is particularly an issue as enterprises cram
more servers into the same square footage through the
use of rack-dense architectures, such as blade servers."
If you're debating whether to go for the market leader
or one of the upcoming competitors, consider what New
Pig Corp., a plant maintenance and safety firm headquartered
in Tipton, Penn., is doing to harness the best of both
worlds. It set up NetBotz probes to monitor temperature,
airflow, humidity, and room access, but it also has some
BitSight devices for temperature and humidity. WebNM network
management software from Somix Technologies controls both
sets of devices. Soon after being installed, the technology
proved its worth.
"The air stopped working on a Saturday," says
Steve Luciano, network administrator for New Pig. "When
we arrived on site, the temperature in the server room
was over 90 degrees."
Many environmental sensor adopters, though, are not so
lucky. Like going to the dentist when you have an abscessed
tooth, most enterprises leave the purchase until after
a system failure that could have been prevented had the
equipment been in place. With the price point on the latest
crop of devices, one set of probes is unlikely to cost
more than one minor downtime incident.
"If the server room is to be remotely managed, or
if it is a lights out operation, some kind of environmental
monitoring is essential," concludes Quorcirca's Collins.