When to Reboot

Someday, people will read this essay and lack the context to understand it — their hardware and software will work reliably. Until that day comes, the information in this essay will be valuable.

Standard advice to people experiencing computer problems is to reboot. I’ve known technicians who refuse to even listen to a question if people haven’t rebooted. It’s simply amazing how many problems in the Windows world can be fixed that way. Modern PCs like to be rebooted every couple of days or so — it used to be daily, with Windows 98, so at least it’s gotten a little better. No sysadmin I know lets a Windows box go longer than a month without rebooting under any circumstance. (If you have longer than a month of uptime on Windows, you’re probably not installing security updates.)

Macintosh OS X boxes and Linux/Unix boxes seem to have much greater reliability, and need a reboot much more seldom than their Windows brethern. Still, even on Linux and Macintosh boxes, the occasional reboot solves all kinds of problems. (If you’re savvy enough to object that a reboot destroys valuable forensic evidence that lets you identify the cause of the problem, you’re right — but you’re also savvy enough to figure out when to reboot on your own. This essay isn’t written for you.)

Still, there’s some things about rebooting you need to keep in mind. First of all, it’s not a panacea. There’s many things it can’t fix. Many more are fixed only temporarily by a reboot — if you’re having to reboot three times a day, it’s time to get someone in there who knows what they’re doing to take a look at the thing.

There’s times when you shouldn’t be too quick to reboot, either. Some processes can take a while to complete. This is especially true if you’re doing something over the network. There are no hard-and-fast rules, and in some very specific conditions you would wait much longer, but in general five minutes is long enough for your computer to do just about anything. I’m speaking here of waiting for your computer with no visible response — if my computer has a moving progress bar, I never reboot unless the wait time is much, much, much longer than than my experience tells me it should be and the program doesn’t respond to a cancel command.

Telling whether a computer is frozen or merely working hard (or pausing for dramatic effect) can be difficult, even for advanced techs. One trick is to look at signs on the computer other than the video display. (Assuming that the video display appears frozen.) Can your hear the hard drive or DVD drive spinning? Regular whining of the drive spinning idly, or the irregular sound of the drive mechanism seeking data? Flickering activity LEDs on the front of the case for hard drives and CD drives, and other disks? Ones on the back for network or other activity lights?

I’ve been able to tell by putting my hand on the computer itself and feeling the vibration of the hard or DVD drive. (Doesn’t work with every case.) Sometimes when trying to boot a computer from a CD I’ll be able to hear whether it’s booting from the hard drive or from the CD as intended. If the computer gets really frozen the Caps Lock (and Num Lock and Scroll Lock, if present) LEDs on the keyboard won’t change when you hit the corresponding key. That means reboot for sure. For the borderline cases, wait five minutes longer than you think you should and reboot.