Uncertain power conditions can wreak havoc on small businesses,
however, there are ways to limit the risk of computer data
loss
Today, the power problems facing a network manager are too
numerous and too complex for a simple UPS-only solution. The most
common power problems facing the network manager and user
include:
Loss of data/information Notification of utility outages and power
related eventsIncreasing network complexityLimited resources to
manage the networkThe need to understand and diagnose power
problemsToday's sophisticated network power management software
products, when used in conjunction with a UPS, can solve these
problems. Alternatives and trade-offs between higher end software
solutions and entry-level products will be examined.
Loss of
data/informationThe first and most important problem facing the
network manager is the loss of data or information. In fact,
according to Contingency Planning Research, "Forty-five per cent of
computer data loss in the US is due to power outages and surges".
Protection by a UPS is adequate unless the power outage lasts
longer than the battery in the UPS will provide power to the
computer. Should a computer suddenly be without power, it, of
course, stops functioning. With some sophisticated operating
systems, such as UNIX, the impact goes beyond simply the system
turning off. Mission critical data files and even the operating
system itself can be corrupted, leaving the network manager or user
with the task of trying to figure out what has been affected and
then taking the necessary corrective action. It may even require
that the operating system be re-installed. With the potential for
many users to be unable to perform their respective tasks while
waiting for the problems to be resolved, the company faces
significant loss of productivity and the resulting revenue and
profits.Today's network power management software products, whether
it be high-end or entry-level, all provide for a graceful shutdown
of the operating system and closing of all open applications and
files in the event of an extended electrical failure, thus
protecting the critical information from loss or corruption. They
also provide configurable shutdown parameters, which allows the
user to select how much time to spend on battery prior to beginning
the shutdown process, and usually turn off the UPS to prevent
complete discharge of the battery, which shortens battery life. By
choosing a more sophisticated package, a shutdown sequence may also
be customised to execute a particular command prior to bringing
down the system. This feature allows for stopping applications in
order of a priority scheme determined by the user.
Notification
of utility outages and power related eventsAside from shutting
down the computer properly, one of the next most important problems
to address is rapid notification of people who are affected by a
changing power condition. The first and most important feature is
notification of users so that they have an opportunity to save
their work before the system shuts down. This feature is standard
in most power protection software packages. With more advanced
packages, notification via email or paging is included. This allows
a network manager to be notified remotely of a power related
problem and provides an opportunity to perform any specific system
management activities prior to shutdown either on-site or using a
remote connection.A high-end package may also provide notification
via Simple Network Management Protocol (SNMP) traps. SNMP is an
evolving standard for network management which has seen increasing
acceptance recently. A trap is a message which is sent to an SNMP
supported network management software package, such as IBM's
NetView for AIX, Hewlett-Packard's OpenView or Sun Microsystems'
SunNet Manager, which gives a brief statement/alert describing
power condition. In this manner, a network manager receives the
information in a form consistent with other network-related
messages.Communication with network adaptor products is also a
consideration. Network adaptor products connect an UPS directly to
a network, which allows for protection of non-computer devices. By
using a network power management software package, a network
manager can monitor and reboot a remote UPS, cycling power to a
device which initiates a reset (sometimes required to get a device
to function properly). This feature provides control of a UPS (and
protected equipment) which may be literally half-the-world away.
Some more advanced software packages also permit communication with
adaptors to allow multiple computers to be powered by one UPS and
still shutdown properly upon utility failure. Potential cost and
space savings may be realised through this configuration.Network
managers should look at the needs for notification carefully,
paying particular attention to potential future requirements, such
as SNMP communication, when selecting a network power management
software package.
Increasing network complexityAs networks
become more complex, network managers have the increasingly
difficult task of maintaining consistent software solutions across
hardware platforms. Whether an entry-level basic package is
selected or a higher end package is used, a software vendor needs
to support the wide variety of operating systems that may be found
across an enterprise. For true WAN protection, users should select
packages, which can communicate across network devices such as
bridges and routers. Also, with mixed networks, such as those
having computers running both NetWare and UNIX becoming more
prevalent, packages which provide this internetworking capability
are certainly worth careful consideration. Integration with network
management software packages, such as NetView for AIX or HP's
OpenView, can be desirable because it means easier operation. A
graphical user interface (GUI) also helps speed installation,
configuration and use of the software.
Limited resources to
manage the networkWith today's downsizing and streamlining of
organisations coupled with the trend toward distributed computing,
network managers are faced with the fact that they will be expected
to effectively manage an increasingly complex network with no
proportional increase in resources or, perhaps, even fewer
resources. In a situation with a large number of protected
computers or network devices spread geographically, one of the most
important features to look for is remote monitoring capability.
Using remote monitoring and advanced features such as notification
via SNMP traps, network managers can monitor the power
enterprise-wide from a single workstation. In some higher end
packages, remote retrieval of battery information is also possible,
making planning for maintenance of UPSs much easier. Advanced
packages also should contain a scheduled shutdown/restart feature,
which will safely shutdown and restart the system on a daily,
weekly or on an exception (for holidays) basis for energy
conservation or security purposes. For example, a user could select
to shutdown a server (and power-off the UPS) Fridays at 6pm and
restart on Mondays at 7am. Depending on the rate of power
consumption and power cost, significant power cost savings could be
realised. System security is increased because the computer and UPS
are automatically brought down and powered-off during times when no
users are present.
Need to understand and diagnose power
problemsOf all the topics related to power protection,
detecting and solving power problems before they happen is perhaps
the most desirable and the most difficult to achieve. Advanced
network power management software packages do take a first step at
tackling this issue by providing a log of power events that have
occurred over a period of time. Using this data, an analysis can be
performed to spot trends and resolve chronic power problems. Some
advanced packages also contain a battery test that can be performed
automatically every month, for example, to get an early warning of
a potential battery problem. To visually represent power parameters
and detect and diagnose power quality problems, some advanced
packages also contain real-time meters and power waveform graphs.
The meter graphs show values for typical power parameters, such as
voltage and frequency over time. A power waveform graph gives a
visual indication of power quality by a comparison of the incoming
sine wave versus the outgoing sine wave. A calculation of the total
harmonic distortion (a measure of power quality) can also be
performed. These features are useful to the more advanced,
power-oriented user to analyse power issues.Although these features
are useful to analyse repeated power problems, there is no way to
foresee a totally random event. The best method to protect a system
is to select a UPS which has the level of protection desired,
considering the benefits of online versus other technologies, and
choose an appropriate network management software
package.
ConclusionSolving today's power protection problems
in an increasingly complex environment, requires a total system
approach combining UPS hardware and power management software.
Network managers should carefully consider the problems they face
and select the software solution that not only meets today's needs,
but also allows for possible expansion, including such features as
the use of a standard communication protocol and diagnostic tools.
Developing a checklist of the "must have" and "nice to have"
features is one simple way of ensuring that the needs for power
protection are met.
Compiled by Mike Burkitt( 1999
Powerware, Inc.