--- /dev/null
+These scripts are intended to handle both boot time and
+run-time management of system services and general configuration.
+
+In general, the philosophy is to be as simple as possible. The
+admin who has to debug a boottime or service start up script
+that he hasn't looked at in a year and a half and that was set
+up by his predecessor anyway doesn't want something that can't
+be understood with a basic knowledge of init, the shell, and
+a couple of man pages.
+
+A system administrators accumulated knowledge should also be
+respected as far as possible. There is no point in throwing
+away years of experience merely for the sake of being different.
+Further, the system should follow, as much as possible the
+principle of least surprise.
+
+Where possible, configuration scripts should be simple /bin/sh
+compatible files that do nothing other than set variables
+and do not call any programs. This allows other scripts
+to simply source them without any complicated parsing.
+
+However, where existing tools use configuration files that don't adhere
+to that principle, those files and tools should continue to be used
+unchanged. As examples, /etc/fstab, /etc/sysctl.conf.
+
+In keeping with the above, these scripts work as follows:
+
+Run-levels are little used, and so they will be kept to doing
+as little as possible. This system uses the following:
+
+Run Level S: single user mode
+Run Level 1: also single user mode
+Run Level 2: multi user mode, but with as little running as
+might be needed for maintaining the box. Typically this
+will be networking and sshd, but nothing else. For some
+systems even these may not be needed.
+
+Run Level 3: This is the normal "everything running" level.
+Run Level 6: System shutdown
+
+No other run levels are used, though a system admin could
+set them up if needed.
+
+System Scripts
+--------------
+
+These scripts live in /etc
+
+fstab: lists filesystems, this file is not changed from it's usual
+format, and is used as such
+
+rc.sysinit: done once at start time. responsible for performing any
+necessary early system initialization. This reads rc.conf for some
+of its actions
+
+* do any boot time /tmp cleanup or similar
+* fsck and mount filesystems
+* load any kernel modules needed
+* set the host name
+* set up /dev (via udev on modern linux systems)
+* sysctl
+* do any utmp/wtmp initialization needed
+* configure the console
+* set timezone and clock
+
+Since all of this has to be done before we do anything else,
+and the order won't generally change, this can and should be
+a single script.
+
+rc.multi: brings up the system into multi user mode. reads rc.conf
+
+* start any startup scripts listed in DAEMONS
+
+rc.conf:
+
+responsible for setting variables used by other scripts. this script will
+be sourced by several other scripts and thus shouldn't actually perform
+any actions of its own. It can call other programs if needed to set variables,
+but this should be minimized (e.g. it could cat /etc/hostname to set the HOSTNAME
+variable, but shouldn't actually set the hostname, and it would be better to just
+set the hostname directly)
+
+DAEMONS: a set of scripts from /etc/rc.d/init.d to run. These will
+be run in the order listed.
+
+HOSTNAME: the system hostname to set.
+
+TZ: the system time zone
+
+Robustness
+----------
+
+Each daemon start-up script should register somehow the fact that it
+is running and started. A monitoring daemon then should be run *out of init*
+to check these daemons and restart them if they crash. If the monitor
+is not run from init, it could itself crash. This should perhaps be
+run level 4 for this daemon. Ideally, nothing would be run as a daemon
+and init could handle the monitoring itself, but this would be a major
+change to the usual practice.
projects / startuptools / blobdiff