Configuration Files 235lucky, whitespace. If you choose the wrong separator, the program reading
the configuration file will usually silently die, trash its own data files, or
ignore the rest of the file. Rarely will it gracefully exit and report the exact
problem. A different syntax for each file ensures sysadmin job security. A
highly paid Unix sysadmin could spend hours searching for the difference
between some spaces and a tab in one of the following common configura-
tion files. Beware of the sysadmin claiming to be improving security when
editing these files; he is referring to his job, not your system:
Multiple Machines Means Much Madness
Many organizations have networks that are too large to be served by one
server. Twenty machines are about tops for most servers. System adminis-
trators now have the nightmare of keeping all the servers in sync with each
other, both with respect to new releases and with respect to configuration
files. Shells scripts are written to automate this process, but when they err,
havoc results that is hard to track down, as the following sysadmins testify:
From: Ian Horswill <[email protected]>
Date: Mon, 21 Sep 92 12:03:09 EDT
To: [email protected]
Subject: Muesli printcapSomehow Muesli’s printcap entry got overwritten last night with
someone else’s printcap. That meant that Muesli’s line printer dae-
mon, which is supposed to service Thistle, was told that it should
spawn a child to connect to itself every time someone tried to spool
to Thistle or did an lpq on it. Needless to say Muesli, lpd, and Thistle
were rather unhappy. It’s fixed now (I think), but we should make
sure that there isn't some automatic daemon overwriting the thing
every night. I can’t keep track of who has what copy of which, which
they inflict on who when, why, or how./etc/rc /etc/services /etc/motd
/etc/rc.boot /etc/printcap /etc/passwd
/etc/rc.local /etc/networks /etc/protocols
/etc/inetd.conf /etc/aliases /etc/resolv.conf
/etc/domainname /etc/bootparams /etc/sendmail.cf
/etc/hosts /etc/format.dat /etc/shells
/etc/fstab /etc/group /etc/syslog.conf
/etc/exports /etc/hosts.equiv /etc/termcap
/etc/uucp/Systems /etc/uucp/Devices /etc/uucp/Dialcodes