#!/bin/sh
#
# Take the system down for backups and then bring it back up.
# Expects a single (possibly empty) argument X which is used to select
# a file /etc/backup/warnings.X. This file will contain lines like:
# T 300 "in 10 minutes"
# T 240 "in 5 minutes"
# T 45 "in 1 minute"
# T 15 "in 15 seconds"
# configuring the frequency of warning messages. If you call the 
# files 'warnings.soon', 'warnings.now' and 'warnings.' then
# you can invoke this as:
#   takedown                     lots of warnings
#   takedown soon                not so many warnings
#   takedown now                 no warning at all

set -e
cd /etc/backup

host="`hostname`" || true

T () {
	(
		exec wall <<END &
 *** WARNING - SYSTEM GOING DOWN FOR BACKUPS ***
 $host will shut down automatically $2.

END
	) &
	sleep $1
}

. "warnings.$1"

(
	exec wall <<END &
 *** WARNING - SYSTEM GOING DOWN FOR BACKUPS ***

  $host is shutting down IMMEDIATELY.

END
) &
sleep 1

# We assume that runlevel 5 is set up suitably for doing backups
# (ie non-essential services turned off in an effort to get the
# tape to stream.)
telinit 5