Protect Your Linux Systems With UPS

Protecting your customers' systems from power failure is a good idea. The good news is that you can do it easily, and relatively inexpensively, even with a Linux workstation, assuming you use the right uninterruptible power supply (UPS) and the necessary software.

At first blush, it may seem odd to pick a UPS for software availability. But with Linux, picking a hardware peripheral by Linux software availability is the best way to guarantee a trouble-free software installation and a trouble-free operation afterwards.

First, before you even buy the UPS hardware, find out whether Linux software exists for it. To do so, check the UPS vendor's site for the unit you are considering.

Here are the other desirable features for your UPS:

• Power quality monitoring.

• Orderly shutdown.

• Saving of documents in progress.

• Power-on restart. This is an especially good idea for an unattended server.

• If remote monitoring is possible, make sure it is secure. Ever see somebody shut down your workstation from three time zones away due to a software vulnerability? It can happen.

If you find a UPS system you like, but the vendor doesn't supply Linux UPS software, you may be able to find an open-source software package of network utilities—commonly referred to by developers as "NUT" for Network Utilities Tools—that supports the UPS you're considering. But one consideration, especially for a workstation user, is that many NUT packages are much more difficult to set up.

The Linux distribution on the system I used for this Recipe is Fedora Core 2. But the vendor Linux package described here should work on any mainstream Linux distribution. Also, the open-source package should install easily on any Linux distribution with automated installation and via RPM, source, or tarball (Linux slang for an archive file in tar or tar.gz format, with the gz being a form of ZIP-like compression) on practically any distribution.

Selecting UPS Hardware for Linux

A UPS is essentially a voltage-regulated inverter wrapped around a big battery. The bigger the battery, the longer the uptime of your workstation running on that battery. Since a UPS can expensive, shop around to keep within your budget. For this Recipe, I wanted to keep my total cost below $125.

My previous UPS, a Belkin 425VA, cost about $100, including shipping, when I bought it in early 2001. While the unit still works, after the serial port jack broke off during a move, there wasn't much point in replacing the battery. Given that power electronics don't improve with age, four years of service meant this UPS was ready for retirement. Since my power requirements hadn't changed much—I got a bigger CPU, but had replaced a15-inch CRT monitor a more energy-efficient 17-inch LCD flat-panel—I didn't see a reason to spend much more than I had four years earlier.

I wanted to buy the biggest battery I could find in a UPS that did power conditioning, subject to reliability constraints. In general, a package in the $75 to $150 range from any reputable vendor should serve typical workstation needs: low-to-midrange CPU, single hard drive, DVD drive, and monitor. But if you need more specific guidance, or you're dealing with something bigger than a workstation, many UPS vendors have wizards on their Web sites to assist you in your choice.

I shopped around, but in the end decided to stick with Belkin. It's a reputable brand, and I've had good experience with them. I found a Belkin with storage capacity comparable in price to Cyberpower. So my new UPS is a Belkin Battery Backup with Surge Protection (550VA), Part #F6C550-AVR. I believe the Belkin vendor proprietary package, Bulldog Plus, to be fairly typical for this type of software.