Devoted to hardware, software, IT issues, and information technology management

I just wrote an article about protecting your IT systems from a power failure, Threat Thursday: What About Power?, but thought I would follow up with a multi-part companion post regarding redundant components and failover mechanisms or processes and even reiterate my first paragraph:

Most, if not all, of the equipment supporting a company's IT infrastructure is electromechanical and that means that hardware (hard drives, NICs, network switches, power supplies, servers, even utilities) will eventually fail or experience an outage of some kind.

While the IT department spends quite a bit of money and effort to implement component redundancy (N+1 Redundancy being the best), but when's the last time someone actually tested these to make sure they work as expected?  I'm not saying that we should run around willy-nilly in the data center pulling cables and hot-plug devices.  This should be performed methodically:  I would recommend testing with non-production systems first and only once a recent, known-good, backup is readily available.

Redundant Power Supplies - Hopefully the small expense has been made to purchase them with the equipment originally or as a later retrofit:

• These should be plugged into different power sources, UPS and utility power at least.
• Each power source should be conditioned to guard against spikes, lightning strikes, etc. through the use of a Power Distribution Unit or Surge Suppressor.
• Be cautious as some equipment may require at least two power supplies to function properly.
• Disconnect the power cord to confirm the system continues running.  If not, find out why so that a real power failure or failed power supply doesn't cause unnecessary downtime.

I'll discuss redundant network connections in Part Two.