#!/bin/sh
#
# $Id: LVM.in,v 1.2.4.1 2004/04/20 05:05:29 alan Exp $
# 
# LVM
#
# Description:	Manages an LVM volume as an HA resource
#
#
# Author:	Alan Robertson
# Support:	linux-ha-dev@lists.tummy.com
# License:	GNU Lesser General Public License (LGPL)
# Copyright:	(C) 2002 International Business Machines, Inc.
#
#	This code significantly inspired by the LVM resource
#	in FailSafe by Lars Marowsky-Bree
#
#
# An example usage in /etc/ha.d/haresources: 
#       node1  10.0.0.170 LinuxSCSI::0:0 ServeRAID::1::1 LVM::myvolname
#
# See usage() function below for more details...
#

prefix=/usr
exec_prefix=/usr
#. /etc/ha.d/shellfuncs
. /etc/ha.d/shellfuncs

#
#
#
unset LC_ALL; export LC_ALL
unset LANGUAGE; export LANGUAGE

usage() {
  methods=`LVM_methods | grep -v methods`
  methods=`echo $methods | tr ' ' '|'`
  cat <<-! >&1
	usage: $0 <LVM-configuration file> ($methods)
	usage: $0 methods

	$0 manages an  Linux Volume Manager volume (LVM) as an HA resource

	The 'start' operation brings the given volume online
	The 'stop' operation takes the given volume offline
	The 'status' operation reports whether the volume is available
	The 'monitor' operation reports whether the volume seems present
	The 'methods' operation reports on the methods $0 supports

	$Id: LVM.in,v 1.2.4.1 2004/04/20 05:05:29 alan Exp $
	!
  exit 1

}

#
#	run:  run a script, and log its output.
#
run() {
  output=`"$@" 2>&1`
  rc=$?
  output=`echo $output`
  if
    [ $rc -eq 0 ]
  then 
    if
      [ ! -z "$output" ]
    then
      ha_log "info: $output"
    fi
    return 0
  else
    if
      [ ! -z "$output" ]
    then
      ha_log "ERROR: $output"
    else
      ha_log "ERROR: command failed: $*"
    fi
    return $rc
  fi
}



#
# methods: What methods/operations do we support?
#
LVM_methods() {
  cat <<-!
	start
	stop
	status
	monitor
	methods
	!
}

#
#	Return LVM status (silently)
#
LVM_status() {

  vgdisplay $1 | grep -i 'Status.*available' >/dev/null
  
}

#
#	Report on LVM volume status to stdout...
#
LVM_report_status() {

  VGOUT=`vgdisplay $1 2>&1`
  if
    echo "$VGOUT" | grep -i 'Status.*available' >/dev/null
  then
    : Volume $1 is available
  else
    echo "LVM Volume $1 is not available (stopped)"
    return 1
  fi
  if
    echo "$VGOUT" | grep -i 'Access.*read/write' >/dev/null
  then
    echo "Volume $1 is available read/write (running)"
  else
    echo "Volume $1 is available read-only (running)"
  fi
  
  
}

#
#	Monitor the volume - does it really seem to be working?
#
#
LVM_monitor() {

  if
    LVM_status $1
  then
    : OK
  else
    ha_log "ERROR: LVM Volume $1 is offline"
    return 1
  fi

  run vgck $1
}

#
#	Enable LVM volume
#
LVM_start() {

  ha_log "Activating volume group $1"
  run vgscan $1
  run vgchange -a y $1 || return 1

  if
    LVM_status $1
  then
    : OK Volume $1 activated just fine!
    return 0
  else
    ha_log "ERROR: LVM: $1 did not activate correctly"
    return 1
  fi
}

#
#	Disable the LVM volume
#
LVM_stop() {

  ha_log "Deactivating volume group $1"
  run vgchange -a n $1 || return 1

  if
    LVM_status $1
  then
    ha_log "ERROR: LVM: $1 did not stop correctly"
    return 1
  fi
  return 0
}


#
#	'main' starts here...
#

if
  [ $# -eq 1 -a "methods" = "$1" ]
then
  LVM_methods
  exit $?
fi

VOLUME=$1

# What kind of method was invoked?
case "$2" in

  start)	LVM_start $1
		exit $?;;

  stop)		LVM_stop $1
		exit $?;;

  status)	LVM_report_status $1
		exit $?;;

  monitor)	LVM_monitor $1
		exit $?;;

  methods)	LVM_methods
		exit $?;;
esac

usage