UNIX System Administration Handbook - Evi Nemeth [488]
3. Backups can be subpoenaed; you might want to expire some backup images.
4. The number for the 1992 survey was 47.5 hours per week, although that survey disregarded responses greater than 70 hours/week on the theory that those numbers were not sustainable.
5. MX refers to a mail exchanger record in DNS, not to a serial connector.
6. xlock is a locking screen saver program for the X Windows system that requires you to type your password or the root password to unlock the screen.
7. Years ago, a major upgrade from Sun changed the formatting of the disks, and thanks to a bug in the format program, we could not back out the upgrade. We have not installed the first version of a major release since that experience.
8. Perhaps DoubleClick.net could beat them to the punch by patenting double-clicking...
9. The title of this document might change; it’s not due out until late 2000.
27.17 RECOMMENDED READING
BURGESS, MARK. “Cfengine: a site configuration engine.” USENIX Computing Systems, Vol 8, No 3. 1995.
BURGESS, MARK. “Computer Immunology.” LISA 1998 proceedings.
OETIKER, TOBIAS. “SEPP – Software Installation and Sharing System.” LISA 1998 proceedings.
SAN DIEGO SUPERCOMPUTER CENTER. Local policies, standards, and procedures. http://security.sdsc.edu/help/SGs.shtml
M.I.B.H., INC. “Acceptable Use Policy.” http://www.mibh.net/mibh-aup.html
M.I.B.H. was acquired by Metromedia Fiber Network, but its AUP is still available on-line and is a good example of a fairly militant policy.
EATON, DAVID W. “comp.software.config-mgmt FAQ, part 3.”http://www.iac.honeywell.com/Pub/Tech/CM/PMTools.html
This FAQ contains a summary of trouble ticketing systems, including many commercial ones we had never heard of. It seems to be well maintained but didn’t contain any of our favorites.
HARROW, JEFFREY R., AND COMPAQ COMPUTER CORPORATION. The Rapidly Changing Face of Computing (periodical). http://www.compaq.com/rcfoc
This regularly updated site contains some interesting articles about technology-related issues. It’s a combination of news and editorial content.
28 Daemons
Although UNIX provides a versatile and generic multitasking environment, the kernel itself lacks the vivid personality and functionality that folks look for when choosing an operating system to be their lifelong companion. Fortunately, UNIX systems come bundled with a rich set of daemons that provide much-needed vitality and flair. The system administrator can also add many additional daemons, whether downloaded, supplied by a vendor, or written by a user.
A daemon is a background process that performs a specific function or system-related task. In keeping with the UNIX philosophy of modularity, daemons are programs rather than parts of the kernel. Many daemons start at boot time and continue to run as long as the system is up. Other daemons are started when needed and run only as long as they are useful.
“Daemon” was first used as a computer term by Mick Bailey, a British gentleman who was working on the CTSS programming staff at MIT during the early 1960s.[1
] Mick quoted the Oxford English Dictionary in support of both the meaning and the spelling of the word. The words “daemon” and “demon” both come from the same root, but “daemon” is an older form and its meaning is somewhat different. A daemon is an attendant spirit that influences one’s character or personality. Daemons are not minions of evil or good; they’re creatures of independent thought and will. Daemons made their way from CTSS to Multics to UNIX, where they are so popular that they need a superdaemon (inetd) to manage them.
This chapter presents a brief overview of the most common UNIX daemons. Not all of the daemons listed here are supplied with all versions of UNIX, and not every daemon supplied with some version of UNIX is listed here. Besides making you more aware of how UNIX works, a knowledge of what all the various daemons do will make you look really smart when one of your users asks, “What does xntpd do?”
Before