#!/bin/bash
#
# $Id: analyze-my-lvm 729 2006-07-30 14:06:39Z bruno $
#

#------------------------- ANALYZE-MY-LVM ----------------------- Hugo Rabson
# 07/14
# - no longer blank first 4k of /dev/mdX
#
# 06/14/2004
# - fixed "n >= 2.00" bug (shell doesn't handle floating points properly)
# - handle dm_mod as well as dm-mod
#
# 02/18/2004
# - nice patch to fix ListAllVolumeGroups() --- J. Richard
# - patch to support LVM2 by Takeru Komoriya
#
# 10/15/2003
# - fixed '-L'-handling to allow for floating-point gigabyte values
#
# 01/15/2003
# - patch (LVM) by Brian Borgeson
#
# 12/10/2002
# - patch by Benjamin Mampaey
#
# 09/05/2002
# - additional patch by Ralph Gruwe
#
# 08/30/2002
# - modified by Ralph Gruwe
#
# 10/01/2001
# - last modified by Hugo :)
#------------------------------------------------------------------------------

Die() {
	echo "$1" >> /dev/stderr
	exit 1
}



GetValueFromField() {
	local res
	sed s/'    '/~/ "$1" | tr -s ' ' ' ' | sed s/'~ '/'~'/ | grep -i "$2~" | cut -d'~' -f2,3,4,5 | tr '~' ' ' | gawk '{ if ($2=="MB") {printf "%dm",$1;} else if ($2=="KB") {printf "%dk",$1;} else if ($2=="GB") {printf "%dg",$1;} else {print $0;};}'
}


GetLastBit() {
	local i res
	i=20
	res=""
	while [ ! "$res" ] ; do
		i=$(($i-1))
		res=`echo "$1" | cut -d'/' -f$i`
	done
	echo "$res"
}


ProcessLogicalVolume() {
	local LV_full_string fname logical_volume volume_group device
	LV_full_string=$1
	[ ! -e "$1" ] && Die "Cannot find LV file $1"
	volume_group=`echo "$LV_full_string" | cut -d'/' -f3`
	logical_volume=`echo "$LV_full_string" | cut -d'/' -f4`
	if [ $lvmversion = 2 ]; then
		device=$LV_full_string
		params=`GenerateLvcreateParameters $device`
	else
		fname=/proc/lvm/VGs/$volume_group/LVs/$logical_volume
		if [ ! -e "$fname" ] ; then
	    	echo "Warning - cannot find $volume_group's $logical_volume LV file"
		else
	    	device=`GetValueFromField $fname "name:"`
	    	params=`GenerateLvcreateParameters $device`
		fi
	fi
	echo "# $LVMCMD lvcreate$params -n $logical_volume $volume_group"
}


GenerateLvcreateParameters() {
	local device stripes stripesize device fname allocation output readahead
	fname=/tmp/PLF.$$.txt
	device=$1
	output=""
	$LVMCMD lvdisplay $device > $fname
	stripes=`GetValueFromField $fname "Stripes"`
	stripesize=`GetValueFromField $fname "Stripe size (MByte)"`m
	[ "$stripesize" = "m" ] && stripesize=`GetValueFromField $fname "Stripe size (KByte)"`k
	[ "$stripesize" = "k" ] && stripesize=""
	allocation=`GetValueFromField $fname "LV Size"`
	[ ! "`echo "$allocation" | grep "[k,m,g]"`" ] && allocation="$allocation"m
	if echo "$allocation" | grep -x ".*g" > /dev/null 2> /dev/null ; then
		val=`echo "$allocation" | sed s/g//`
		allocation=`echo "$val" | awk '{c=$1; printf "%d", c*1024;}'`m
	fi
	readahead=`GetValueFromField $fname "Read ahead sectors"`
	rm -f $fname
	[ "$stripes" ]    && output="$output -i $stripes"
	[ "$stripesize" ] && output="$output -I $stripesize"
	[ "$allocation" ] && output="$output -L $allocation"
	[ "$readahead" ]  && output="$output -r $readahead"
	echo "$output"
}



GenerateVgcreateParameters() {
	local current_VG device fname incoming VG_info_file max_logical_volumes max_physical_volumes physical_extent_size output blanklines
	current_VG=$1
	VG_info_file=/tmp/$$.vg-info.txt
	$LVMCMD vgdisplay $current_VG > $VG_info_file
	max_logical_volumes=`GetValueFromField "$VG_info_file" "MAX LV"`
	[ $max_logical_volumes -ge 256 ] && max_logical_volumes=255
	max_physical_volumes=`GetValueFromField "$VG_info_file" "MAX PV"`
	[ $max_physical_volumes -ge 256 ] && max_physical_volumes=255
	physical_extent_size=`GetValueFromField "$VG_info_file" "PE Size"`
	output=""
	[ "$max_logical_volumes" ]  && output="$output -l $max_logical_volumes"
	[ "$max_physical_volumes" ] && output="$output -p $max_physical_volumes"
	[ "$physical_extent_size" ] && output="$output -s $physical_extent_size"
	echo "$output"
	rm -f $VG_info_file
}





ProcessVolumeGroup() {
	local current_VG physical_volumes i list_of_devices VG_params
	current_VG=$1
	if [ $lvmversion = 2 ]; then
		VG_params=`GenerateVgcreateParameters $current_VG`
		list_of_devices=`$LVMCMD pvs | grep "$current_VG" | awk '{print $1}'`
	else
		info_file=/proc/lvm/VGs/$current_VG/group
		physical_volumes=`ls /proc/lvm/VGs/$current_VG/PVs`
		VG_params=`GenerateVgcreateParameters $current_VG`
		list_of_devices=""
		for i in $physical_volumes ; do
	    	fname=/proc/lvm/VGs/$current_VG/PVs/$i
	    	device=`GetValueFromField $fname "name:"`
	    	list_of_devices="$list_of_devices $device"
		done
	fi
	echo "# $LVMCMD vgcreate $current_VG$VG_params $list_of_devices"
	echo "# $LVMCMD vgchange -a y $current_VG"
}



ListAllPhysicalVolumes() {
	if [ $lvmversion = 2 ]; then
		$LVMCMD pvscan 2> /dev/null | grep 'PV' | awk '{print $2}'
	else
		pvscan 2> /dev/null | grep '"' | cut -d'"' -f2
	fi
}


ListAllVolumeGroups() {
	$LVMCMD vgdisplay 2> /dev/null | awk '/^ *VG Name/ {print $3;}'
}


ListLvmDrivesAndPartitions() {
	$LVMCMD vgdisplay -v |grep "PV Name" | sed 's/(#)//' | awk '{print $3}'
}



PrettifyList() {
	local i
	echo -en "$1"
	for i in $2 ; do
		echo -en "$i "
	done
	echo ""
}


ListAllLogicalVolumes() {
	if [ $lvmversion = 2 ]; then
		$LVMCMD lvscan | grep "'" | cut -d"'" -f2
	else
		lvscan | grep '"' | cut -d'"' -f2
	fi
}



WriteShutdownScript() {
	local i
	echo ""
	echo "Finally, to shut down and delete the volumes, do this:-"
	for i in `ListAllLogicalVolumes` ; do
	    echo "($LVMCMD lvremove -f $i)"
	done
	for i in `ListAllVolumeGroups` ; do
	    echo "($LVMCMD vgchange -a n $i)"
	done
	for i in `ListAllVolumeGroups` ; do
	    echo "($LVMCMD vgremove $i)"
	done
	if [ $lvmversion = 2 ]; then
		echo "(rmmod dm-mod & rmmod dm_mod & )"
	else
		echo "(rmmod lvm-mod)"
	fi
}



# -------------------------------- main -----------------------------------
which lvmdiskscan 2>/dev/null 2>&1 || Die "Cannot find lvmdiskscan. Are you sure you're using LVM?"
if [ -e "/proc/lvm/global" ] && [ "`tr -s '\t' ' ' < /proc/lvm/global | grep "0 VGs 0 PVs 0 LVs"`" != "" ] ; then
	exit 0
fi

lvmversion=`lvmdiskscan --help 2>&1 |
  grep -E "Logical Volume Manager|LVM version:" |
  cut -d: -f2 | cut -d. -f1 |
  awk '{print $NF}' |
  sed -e 's/ //g'`

if which lvm 2>/dev/null; then
	version=`lvm version | grep "LVM version" | awk '{print $3}'`
	i="`echo "$version" | cut -d'.' -f1`"
	echo "i=$i"
	if [ "$i" -ge "2" ] ; then
		lvmversion=2
	fi
fi

if [ $lvmversion = 2 ]; then
	echo "LVM version >= 2.0 found."
	LVMCMD="lvm"
else
	LVMCMD=""
fi

all_lvm_drives_and_partitions=`ListLvmDrivesAndPartitions`
echo "Just before you extrapolate mountlist to include RAID partitions,"
echo "extrapolate it to include the following LVM drives and partitions:-"
PrettifyList ">>>>> " "$all_lvm_drives_and_partitions"
echo "To get started, type:-"
if [ $lvmversion = 2 ]; then
	echo "(insmod dm-mod)"
	echo "(insmod dm_mod)"
else
	echo "(insmod lvm-mod)"
fi
echo "# $LVMCMD vgchange -an"
for i in `ListAllPhysicalVolumes` ; do
	echo "# echo y | $LVMCMD pvcreate -ff $i"
done
echo "# $LVMCMD vgscan"
echo ""
echo "Create and activate the VG's (volume groups)."
all_volume_groups=`ListAllVolumeGroups`
for current_VG in $all_volume_groups ; do
	if [ $lvmversion -ne 2 ]; then
	    echo "# rm -Rf /dev/$current_VG"
	fi
	ProcessVolumeGroup $current_VG
done
echo ""
echo "Finally, create the LV's (logical volumes)."
all_logical_volumes=`ListAllLogicalVolumes`
for current_LV in $all_logical_volumes ; do
	ProcessLogicalVolume $current_LV
done
echo ""
echo "# $LVMCMD vgscan"
echo "Now you may format the LV's:-"
for i in `ListAllLogicalVolumes` ; do
	echo "(mkfs -t foo $i or something like that)"
done
WriteShutdownScript
exit 0