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Raritan Dominion PX8

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The Raritan Dominion PX keeps track of power consumption, and records temperature and humidity data from sensors placed amongst your servers. When combined with an un-interruptible power supply, we think it will keep your servers safe and happy.

We always ask what our computers can do for us, but do we ever stop and think about what we can do for them? Being kind to your equipment will result in better reliability and a reduced likelihood of failure.

A quick look at the specifications for your equipment will show acceptable temperature and humidity levels, but have you been checking these environmental factors regularly — or at all? Hot equipment is equipment heading for failure — do you know where the heat is coming from? In server racks, heat from each machine can contribute to the discomfort of neighbouring devices.

Test procedure
We mainly assessed the ease of use for this device, but in addition we checked that temperature and power consumption readings were accurate.

Usability includes initial set-up and configuration issues as well as the ease with which data-logs can be accessed. We compared the power readings against two power meters and the temperature against an optical thermometer. We also assessed documentation quality and the level of expertise required to use the device.

Design and features
The Dominion PX series are Power Distribution Units (PDUs), which come in zero Rack Units (RU), 1U and 2U models with eight to 20 outlets. We reviewed, the PX8 model, which was a 1RU model bearing eight power outlets. The power inlet has a fixed cord with screw-in plug. Each rear-mounted outlet nestles beside a tricolour status LED and the front of the device bears three RJ-45 sockets for connection to environment sensors, telnet, and a LAN.

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Set up is not a major drama, but you will probably want to use a network sniffer if using DHCP. The device has a default IP address, but will use DHCP where possible. The alternative is to use telnet to get in and assign the address via com-port — which is a legacy technology and a painful experience. (We spent a happy half-hour looking for a PC with both a com-port and an OS other than Vista — Microsoft in its infinite wisdom no longer includes HyperTerminal in its OS.)

Once you have it all plugged in and you have managed to locate the network address, it is a simple matter of logging into the management interface via a Web browser.

Critical power or environmental changes as well as log-ins and other administrative events are recorded in an event log. It is possible to accurately define what events are recorded and how the system should respond. For example, you can specify what humidity and temperature levels are unacceptable (both upper and lower limits) and these events may simply be logged or a message may be sent to an administrator via e-mail.

In critical cases you may set the system to automatically shut-down power to certain devices for an extended period, or momentarily to force a reboot. If necessary you can limit the amount of power to particular outlets — thus ensuring other critical systems don't go without. You can cycle power between supplies where devices have multiple power supplies.

Using PX trend analysis software it is possible to hunt down servers which are constantly using little power (indicating that they may not be being used) and may discover that power distribution could be better balanced between adjacent racks.

Other software with SNMP can be used to access data from the device for more advanced reporting. Also, the Dominion is compatible with the IPMI protocol allowing for detailed interrogation and commands to be sent without manual intervention — you can download free OpenSource client software (for Linux) from Sourceforge.

The Dominion has its own firewall to limit access to specified IP ranges. Access is password protected and multiple user accounts with differing permission levels can be created. It is also important to note that rules can be employed to enforce strong passwords. Further security can be applied by enforcing a HTTPS connection. Identity verification can employ Digital certificates, LDAP and RADIUS protocols, and when using multiple units are required to assess your server banks, the devices can be networked to simplify management and data collection.

Basic management tasks can be achieved with a minimum of expertise. If you just want to know when conditions go critical you can just plug everything in, set the desired alert levels for each user, give the machine e-mail privileges and wait for it to inform you when trouble strikes.

If you want detailed energy and environmental logs you'll want staff familiar with server management to set up something like OpenIPMI. Whatever your needs, this device will offer great peace of mind. Combined with an un-interruptible power supply you will have very safe and happy servers.

Temperature and power usage readings appear to be accurate. Raritan only claim five percent accuracy on power levels and our readings were certainly within five percent of those made by the Dominion PX8.

With models in this range starting from AU$713, these machines will be welcome additions to any server rack — particularly in situations where there is reason to suspect trouble (eg, tropical environments, dense server packing or unreliable supply power). Raritan offers a generous two-year warranty with both phone and e-mail-based support as well as extensive online documentation and FAQs.