Make snapshotLC sh

#!/bin/bash
# ----------------------------------------------------------------------
## (c) 2007, Pfalzwolf for www.linux-club.de
## Idea:
##	Mike Rubel 2004.01.04
##
## License:
##	use this software on your own risk, it works for me but there
##      are no guaranties at all
## ----------------------------------------------
##
## make_snapshot: 
##	Backup Script based on rsync
##	It creates Generation Backups for the levels daily, weekly and montly
##
## Version:
##	0.3
##
## Synopsis:
##       make_snapshot [OPTIONS]
##
## Description:
## 	This script was adopted from Mike Rubels documentation from
## 	http://www.mikerubel.org/computers/rsync_snapshots/
##	Based on Mikes handy rotating-filesystem-snapshot utility.
##	The basic idea is it makes rotating backup-snapshots of /home whenever called
##	A few elements came from
##	http://www.heinlein-support.de/web/support/wissen/rsync-backup/
##	An exclude list avoids to backup superflous files.
##
## Changes:
##	Instead of hourly, daily and weekly snapshots, daily, weekly and monthly
##	snapshots are used.
##	Checking the available space on backup media
##	Free configurable number of snapshots for every single level
##	Everything packed into one script
##
## Options:
##	-d make the daily backup plus rotate
##	-w make the weekly backup
##	-m make the monthly backup
##	-h displays a short help text
## 
## Changelog:
##	--------
########################################################################

unset PATH	# suggestion from H. Milz: avoid accidental use of $PATH

# ------------- System Commands used by this script --------------------
ID=/usr/bin/id;
ECHO=/bin/echo;
MOUNT=/bin/mount;
RM=/bin/rm;
MV=/bin/mv;
CP=/bin/cp;
TOUCH=/bin/touch;
RSYNC=/usr/bin/rsync;
DF=/bin/df;
TAIL=/usr/bin/tail;
SED=/bin/sed;
SYNC=/bin/sync;
LOGGER=/bin/logger;
CHMOD=/bin/chmod;
MKDIR=/bin/mkdir;

# ======================= CUSTOMIZING SECTION ==========================
MOUNT_DEVICE=/dev/sda2;                	# Your Mount device
MOUNT_RO=false;				# For write protection set to  true
SNAPSHOT_RW=/DASI/TEST;            	# where to store the backups
EXCLUDES=/home/wolf/nobackup/backup_exclude; # Create the backup_exclude file first!
CHECK_HDMINFREE=true;		       	# Check free space
HDMINFREE=93;				# Make a backup up to this percentage
DAYS=3;					# Number of daily backups -1
WEEKS=2;				# Number of weekly backups -1
MONTHS=3;				# Number of monthly backups -1
# ======================================================================

# Make sure we're running as root
if (( `$ID -u` != 0 )); then { $ECHO "Sorry, must be root.  Exiting..."; exit; } fi

# Check Argument
if [ $# != 1 ] ; then { $ECHO "Error: Wrong number of arguments.  \
Vaild is one out of -d, -w, -m, -h" ; exit; } fi

# Check Customization
if ! [ -b $MOUNT_DEVICE ] ; then { $ECHO "Error: Mount device $EXCLUDES isn't valid" ; exit; } fi
if ! [ -d $SNAPSHOT_RW ] ; then 
	{ $ECHO "Error: Backup Directory $SNAPSHOT_RW missing"; exit; } fi
if ! [ -d $SNAPSHOT_RW/home ] ; then  $MKDIR -p $SNAPSHOT_RW/home; fi
if ! [ -f $EXCLUDES ] ; then { $ECHO "Error: Exclude File $EXCLUDES missing" ; exit; } fi

# Check free space on disk
GETPERCENTAGE='s/.* \([0-9]\{1,3\}\)%.*/\1/';
if $CHECK_HDMINFREE ; then
	KBISFREE=`$DF /$SNAPSHOT_RW | $TAIL -n1 | $SED -e "$GETPERCENTAGE"`
	if [ $KBISFREE -ge $HDMINFREE ] ; then
		$ECHO "Error: Not enough space left for rotating backups!"
		$LOGGER "Error: Not enough space left for rotating backups!"
		exit
	fi
fi

# ------------- The Script itself --------------------------------------

if $MOUNT_RO ; then
	# Attempt to remount the RW mount point as RW; else abort
	$MOUNT -o remount,rw $MOUNT_DEVICE $SNAPSHOT_RW ;
	if (( $? )); then
		$ECHO "Error: could not remount $SNAPSHOT_RW readwrite";
 		exit;
	fi;
fi;


case $1 in
# *********** Daily Backups ********************************************
	-d | -D) $ECHO "Starting Daily Backup..."
	   # Rotating daily snapshots of /home  

	   # Step 1: Delete the oldest snapshot, if it exists:
	   # It is NOT moved to the weekly backups level since you can make hundreds of daily backups
	   if [ -d $SNAPSHOT_RW/home/daily.$DAYS ] ; then
		$RM -rf $SNAPSHOT_RW/home/daily.$DAYS ;
	   fi;

	   # Step 2: Shift all other snapshots(s) by one, if they exist (e.g. 6->7...1->2)
	   OLD=$DAYS;
	   while [ $OLD -ge 2 ] ; do
		OLD=$[$OLD-1]
	   	if [ -d $SNAPSHOT_RW/home/daily.$OLD ] ; then
			NEW=$[ $OLD + 1 ]
 			# Save date
			$TOUCH $SNAPSHOT_RW/.timestamp -r $SNAPSHOT_RW/home/daily.$OLD
              		$MV $SNAPSHOT_RW/home/daily.$OLD $SNAPSHOT_RW/home/daily.$NEW
			# Restore date
			$TOUCH $SNAPSHOT_RW/home/daily.$NEW/.timestamp \
				-r $SNAPSHOT_RW/.timestamp
		fi;
	   done

	   # Step 3: make a hard-link-only (except for dirs) copy of the latest snapshot,
	   # If that exists 0->1
	   if ! [ -d $SNAPSHOT_RW/home/daily.0 ] ; then
		$MKDIR -p $SNAPSHOT_RW/home/daily.0
		$TOUCH $SNAPSHOT_RW/home/daily.0/.timestamp
	   else
		$CP -al $SNAPSHOT_RW/home/daily.0 $SNAPSHOT_RW/home/daily.1 ;
	   fi;

	   # Step 4: rsync from the system into the latest snapshot (notice that
	   # rsync behaves like cp --remove-destination by default, so the destination
	   # is unlinked first.  If it were not so, this would copy over the other
	   # snapshot(s) too!
	   $RSYNC								\
		-va --delete --delete-excluded				\
		--exclude-from="$EXCLUDES"				\
		/home/ $SNAPSHOT_RW/home/daily.0 ;

	   # Check return code
	   # 0 = ok, 
	   # 24 is also ok. It appears if files were changed or deleted while this script runs
	   # Other return codes are Error -- see man (1) rsync
	   if ! [ $? = 24 -o $? = 0 ] ; then
		$ECHO "Error: rsync finished on $MOUNT_DEVICE with errors!"
		$LOGGER "Error: rsync finished on $MOUNT_DEVICE with errors!"
	   fi;

	   # Step 5: update the mtime of daily.0 to reflect the snapshot time
	   $TOUCH $SNAPSHOT_RW/home/daily.0 ;

	   # Finished!
	   $ECHO "Finished rsync backup on $MOUNT_DEVICE..."
	   $LOGGER "Finished rsync backup on $MOUNT_DEVICE..."

	   # For beeing on the secure site...
	   $SYNC;;

	   # And thats it for home.

# *********** Weekly Backup ********************************************
	-w | -W)$ECHO "Starting Weekly Backup..."
	
	   # Step 1: Delete the oldest snapshot, if it exists
	   if [ -d $SNAPSHOT_RW/home/weekly.$WEEKS ] ; then
		$RM -rf $SNAPSHOT_RW/home/weekly.$WEEKS ;
	   fi;
	   
	   # Step 2: shift the middle snapshots(s) by one, if they exist 3->4 ..0->1
	   OLD=$WEEKS;
	   while [ $OLD -ge 1 ] ; do
	 	OLD=$[$OLD-1]
		if [ -d $SNAPSHOT_RW/home/weekly.$OLD ] ; then
			NEW=$[ $OLD + 1 ]
			$MV $SNAPSHOT_RW/home/weekly.$OLD $SNAPSHOT_RW/home/weekly.$NEW ;
		fi;
	   done

	   # Step 3: Make a hard-link-only (except for dirs) copy of
	   # daily.(max), assuming that exists, into weekly.0
	   if [ -d $SNAPSHOT_RW/home/daily.$DAYS ] ; then
		$CP -al $SNAPSHOT_RW/home/daily.$DAYS $SNAPSHOT_RW/home/weekly.0 ;
	   fi;;

# *********** Monthly Backup *******************************************
	-m | -M)$ECHO "Starting Monthly Backup..."
	
	   # Step 1: Delete the oldest snapshot, if it exists
	   if [ -d $SNAPSHOT_RW/home/monthly.$MONTHS ] ; then
	   	$RM -rf $SNAPSHOT_RW/home/monthly.$MONTHS ;
	   fi;
	   
	   # Step 2: Shift the middle snapshots(s) by one, if they exist 6->7 ..0->1
	   OLD=$MONTHS;
	   while [ $OLD -ge 1 ] ; do
		OLD=$[$OLD-1]
		if [ -d $SNAPSHOT_RW/home/monthly.$OLD ] ; then
			NEW=$[ $OLD + 1 ]
			$MV $SNAPSHOT_RW/home/monthly.$OLD $SNAPSHOT_RW/home/monthly.$NEW ;
		fi;
	   done

	   # Step 3: Make a hard-link-only (except for dirs) copy of
	   # weekly.(max), assuming that exists, into monthly.0
	   if [ -d $SNAPSHOT_RW/home/weekly.$WEEKS ] ; then
		$CP -al $SNAPSHOT_RW/home/weekly.$WEEKS $SNAPSHOT_RW/home/monthly.0 ;
	   fi;;

	-h | -H)$ECHO "Usage:
	      make_snapshot -d	Initiates daily backup
	      make_snapshot -w	Initiates weekly backup
	      make_snapshot -m	Initiates monthly backup
	      make_snapshot -h	Displays this text."; exit;;
	
	*) $ECHO "Error: Wrong argument. Vaild is one out of -d, -w, -m, -h" ; exit;;

esac

$ECHO "Backup ended"
if $MOUNT_RO ; then
	# Now remount the RW snapshot mountpoint as readonly
	$MOUNT -o remount,ro $MOUNT_DEVICE $SNAPSHOT_RW ;
	if (( $? )); then 
		$ECHO "Error: Could not remount $SNAPSHOT_RW readonly";
		exit;
	fi;
 fi;