APLawrence.com -  Resources for Unix and Linux Systems, Bloggers and the self-employed

live, dead

© November 2003 Tony Lawrence

Live data is "real" data, sometimes meaning data you can't screw up. "We'll test against live data" vs. "I don't dare test that against live data!".

A dead machine is a non-functional machine: it is crashed, and may be unable to come back up. A "live" machine usually just means it is responding to pings or is obviously "on the network". The intermediate state: running but not on the network, isn't live or dead. It may be "down", and that is also used when the actual state is unknown: you can't see it on the network, so it is "down". It may actually be running fine, and something else is causing you not to see it, but it is still "down" to you until you learn something different. "System down" might be just a specific (but important) application, or it might be the whole machine.

A zombie process is one that shows up as "defunct" in the process table. It isn't really a process at this point; it's nothing more than a slot in the process table and an exit value that nobody bothered to pick up. This comes from creating a process (by forking) and then exiting without waiting for it to finish. When it finally does finish, it becomes a zombie. You can't "kill" a zombie because there's nothing to kill. Init will eventually pick up the exit value and get rid of the process slot.

A zombie machine is one controlled by some program: the implication is that the machine has been hacked and is doing someone else's bidding.

Got something to add? Send me email.

(OLDER)    <- More Stuff -> (NEWER)    (NEWEST)   

Printer Friendly Version

-> live, dead

Inexpensive and informative Apple related e-books:

Take Control of IOS 11

Are Your Bits Flipped?

Digital Sharing Crash Course

Take Control of Apple Mail, Third Edition

Take Control of iCloud

More Articles by © Tony Lawrence

Printer Friendly Version

Have you tried Searching this site?

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us

Printer Friendly Version

C++ is a badly designed and ugly language. It would be a shame to use it in Emacs. (Richard Stallman)

Linux posts

Troubleshooting posts

This post tagged:



Unix/Linux Consultants

Skills Tests

Unix/Linux Book Reviews

My Unix/Linux Troubleshooting Book

This site runs on Linode

SCO Unix Sales, Support, & Service

Phone:  707-SCO-UNIX (707-726-8649Toll Free: 833-SCO-UNIX (833-726-8649)