Washington Apple Pi

© 2003 Lawrence I. Charters

Washington Apple Pi Journal, reprint information

The Pi survives the blackout; can you?

August 2003 was hard on computers. Not only were various worms and viruses bringing millions of Windows computers to their knees, but a massive power outage in the Northeast brought on the largest blackout in history, leaving 50 to 60 million people without power in the U.S. and Canada.

Less than two weeks later, another blackout left roughly 320,000 people without power in Virginia and Maryland. While the much larger Northeast blackout was caused by high heat and overloaded distribution networks, the DC-area blackout was caused by a violent, fast-moving thunderstorm that ripped through the local area, shredding trees, toppling power poles, and generally making a shambles of the evening commute on Tuesday, August 26.

The Pi Office power went out around 4 p.m. Because UPS (uninterruptible power supply) units protected some critical systems, the exact time of the outage isn't clear, but within a few minutes of 4 p.m. it was very, very dark inside the office, and much worse outside. Businesses in the area reported an 'explosion' around that time, though it isn't clear if this was a lightning strike or a transformer failure.

All Pi activity came to a halt. Without power, tutorials were not held, the famed Tuesday Night Clinic didn't take place that evening (though people still traveled to the darkened Pi office, and wondered why no one was there), Special Interest Groups (SIGs) did not meet, the Pi mail server, Web site, and TCS forums vanished from the Internet, and the phones died.

Compared to the tens of thousands who lost the contents of their refrigerators and freezers, and had to endure blazing hot, humid nights without air conditioning, the Pi's problems were modest. Without preamble, the power returned to the Pi shortly after midnight on Thursday, August 28.

All is not well

When the power returned, the Pi's TCS crew had some work to do, and while most Pi members don't operate mail, Web, file and DNS servers, the tasks required apply to anyone with a Mac recovering from a blackout. The first issue: when the power comes back on, check the power. Literally.

If you have a multimeter, switch it to AC and check the power to make sure it is steady. (Radio Shack sells very inexpensive multimeters. Get one.) Utility companies make extraordinary efforts to ensure safe, stable power, but recovery from blackouts is as much art as science and engineering, and it is a good idea to make sure the power is steady. While your Mac will operate on anything from 90 volts to 240 volts, 50 or 60 Hz., it wants a steady supply of power. If the power is not steady, do not plug in your Mac.

You also might need to change the battery. When your Mac is off, it stores critical information in special battery-powered memory. The longer the power is off, the greater the chance the battery will drain and die, especially if it is more than a few years old. Yes, there are stories of original, 128K Mac batteries lasting twelve years, but there are also stories of Power Mac 6100 batteries lasting less than two. Apple's technical documentation suggests the batteries last, on average, three years -- so if your Mac is around this age or older, a moderately long blackout might kill the internal battery.

UPS batteries are also at risk, especially if there was no one around to shut them off when the power went out. UPS batteries are usually lead acid batteries, like car batteries, and like car batteries, if they get drained, they're dead. They can't be recharged, only replaced. If your UPS unit powered your Mac for more than a few minutes during a blackout, you may want to check to see if the battery is fully functional. Otherwise, you may find the UPS can't offer protection from even a half-second brownout.

If your Mac was running when the power went out, and was not shut down gracefully, you'll want to give it a thorough checkup once power is restored. Information that was only partially saved to disk may be scrambled, and the read-write head on the hard drive may have written strange things as it lost power.

For those running Mac OS 7 through 9, run Disk First Aid (the appropriate version for your operating system) and have it check every single hard drive partition. If Disk First Aid finds any problems at all, tell it to repair whatever problems it finds. Repeatedly check and repair all your partitions until no more errors are found. For best results, boot your computer from a bootable CD-ROM and run Disk First Aid from the CD-ROM.

For those running Mac OS X, the procedure is similar. Launch Disk Utility (in the Utilities folder) and use the First Aid portion of the utility to verify all your partitions (and, if necessary, repair them), and repair permissions on your boot partition. For best results (and why settle for anything less?), boot from your installation disc, and run Disk Utility from the CD-ROM.

Once you've checked the health of your hard drive, boot your machine, check to see that the time and date are accurate (inaccuracies suggest either scrambled parameter memory or dead or failing batteries), check to see that your network connections and, if you use a modem, the modem are working, and run some non-critical tasks. Put off doing anything vital until you are sure everything is working.

And if you don't own a multimeter or UPS, head to the store. Blackouts and other disasters don't have to make headlines to cause grief.