Daemons

March 13, Sunday, in my bedroom.

It was seven in the morning when I got a call from our Operations team saying they could not access one of our production servers.

It didn't take long for me to start troubleshooting the problem because I had my laptop next to my bed which was already connected to the office through VPN.

The server keeps on going down because of a memory chip problem. Parts are on their way and it should be fixed soon.

I went in to the server and checked around to see if there is anything else failing besides the hardware. I browsed through all the log files but didn't find any WARNING or ERROR messages pertaining to the problem we're having. I can only see what the problem is through the console. Weird.

Anyway, I checked all the running processes and they were all working fine. Including all the daemons. Daemons: why the hell did they use daemon as a term for a background process? I've known this computer term for over a decade but I never really wondered why it was called a daemon until now.

So I made a research. And I pretty much got everything I needed to know from dictionary.com. So here it is, copied-and-pasted.

dae·mon ( P ) Pronunciation Key (dmn)
n.

1. Chiefly British. Variant of demon.
2. Variant of daimon.
3. Computer Science. A program or process that sits idly in the background until it is invoked to perform its task.

n 1: one of the evil spirits of traditional Jewish and Christian belief [syn: devil, fiend, demon, daimon] 2: a person who is part mortal and part god [syn: demigod]

Source: WordNet ® 2.0, © 2003 Princeton University

daemon

/day'mn/ or /dee'mn/ (From the mythological
meaning, later rationalised as the acronym "Disk And Execution
MONitor") A program that is not invoked explicitly, but lies
dormant waiting for some condition(s) to occur. The idea is
that the perpetrator of the condition need not be aware that a
daemon is lurking (though often a program will commit an
action only because it knows that it will implicitly invoke a
daemon).

For example, under ITS writing a file on the LPT spooler's
directory would invoke the spooling daemon, which would then
print the file. The advantage is that programs wanting files
printed need neither compete for access to, nor understand any
idiosyncrasies of, the LPT. They simply enter their
implicit requests and let the daemon decide what to do with
them. Daemons are usually spawned automatically by the
system, and may either live forever or be regenerated at
intervals.

Unix systems run many daemons, chiefly to handle requests
for services from other hosts on a network. Most of these
are now started as required by a single real daemon, inetd,
rather than running continuously. Examples are cron (local
timed command execution), rshd (remote command execution),
rlogind and telnetd (remote login), ftpd, nfsd (file
transfer), lpd (printing).

Daemon and demon are often used interchangeably, but seem to
have distinct connotations (see demon). The term "daemon"
was introduced to computing by CTSS people (who pronounced
it /dee'mon/) and used it to refer to what ITS called a
dragon.

[Jargon File]

(1995-05-11)

Source: The Free On-line Dictionary of Computing, © 1993-2004 Denis Howe

daemon

/day'mn/ or /dee'mn/ n. [from the mythological meaning,
later rationalized as the acronym `Disk And Execution MONitor'] A
program that is not invoked explicitly, but lies dormant waiting for
some condition(s) to occur. The idea is that the perpetrator of the
condition need not be aware that a daemon is lurking (though often a
program will commit an action only because it knows that it will
implicitly invoke a daemon). For example, under ITS writing a
file on the LPT spooler's directory would invoke the spooling
daemon, which would then print the file. The advantage is that
programs wanting (in this example) files printed need neither
compete for access to nor understand any idiosyncrasies of the
LPT. They simply enter their implicit requests and let the daemon
decide what to do with them. Daemons are usually spawned
automatically by the system, and may either live forever or be
regenerated at intervals.

Daemon and demon are often used interchangeably, but seem to
have distinct connotations. The term `daemon' was introduced to
computing by CTSS people (who pronounced it /dee'mon/) and used it
to refer to what ITS called a dragon; the prototype was a program
called DAEMON that automatically made tape backups of the file
system. Although the meaning and the pronunciation have drifted, we
think this glossary reflects current (2000) usage.

Source: Jargon File 4.2.0

daemon

the Greek form, rendered "devil" in the Authorized Version of the New Testament. Daemons are spoken of as spiritual beings (Matt. 8:16; 10:1; 12:43-45) at enmity with God, and as having a certain power over man (James 2:19; Rev. 16:14). They recognize our Lord as the Son of God (Matt. 8:20; Luke 4:41). They belong to the number of those angels that "kept not their first estate," "unclean spirits," "fallen angels," the angels of the devil (Matt. 25:41; Rev. 12:7-9). They are the "principalities and powers" against which we must "wrestle" (Eph.6:12).