#!/bin/bash
#
#  Author: Mike La Spina
#    Date: Apr 3, 2009
# Version: 0.2
#
# Function: Enumerate active VMFS volumes and create a backup of the header to a file.
#
# Rev 0.1 Initial 
# Rev 0.2 William Lam added folder and rolling backups
###############################################################################

BACKUP_ROTATION_COUNT=10
BACKUP_NAMING_CONVENTION="$(date +%F)"
VMFS_HEADER_BACKUP=/var/log/$(hostname -s)-vmfs-header-backup
VDF_OUTPUT=/tmp/vdf_output

#rotate backup function
checkBackupRotation() {
	local DIR_PATH=$1
	local NAMING_CONVENTION=$2
	LIST_BACKUPS=$(ls -tr ${DIR_PATH})

	#default rotation if variable is not defined
	if [ -z ${BACKUP_ROTATION_COUNT} ]; then
		BACKUP_ROTATION_COUNT=1
	fi

	for DIR in ${LIST_BACKUPS};
	do
		TMP_DIR="${DIR_PATH}/${DIR}"
		TMP=$(echo ${TMP_DIR##*--})

	        if [ ${TMP} = "${NAMING_CONVENTION}" ]; then
	                NEW=${TMP}--1
	                mv "${DIR_PATH}/${DIR}" "${NEW}"
	        elif [ $TMP -ge ${BACKUP_ROTATION_COUNT} ]; then
	                rm -rf "${DIR_PATH}/${DIR}"
	        else
			BASE=$(echo ${TMP_DIR%--*})
	                NEW=${BASE}--$((${TMP}+1))
	                mv "${DIR_PATH}/${DIR}" "$NEW"
	        fi
	done	
}

# create backupdir 
mkdir -p "${VMFS_HEADER_BACKUP}"

# generate mapping of datastore name to UUID
/usr/sbin/vdf -P > "${VDF_OUTPUT}"

# Enumerate the VMFS volumes and create a block copy of the header to a file
/usr/sbin/esxcfg-vmhbadevs -m | awk '{print $2 " " $3}' | while read VMHBADEVS_OUTPUT;
do
	VMFS_DEVICE=$(echo ${VMHBADEVS_OUTPUT} | awk '{print $1}')
	UUID=$(echo ${VMHBADEVS_OUTPUT} | awk '{print $2}')
	DATASTORE=$(grep "$UUID" /tmp/vdf_output | awk -F "%" '{print $2}' | sed 's/^[[:blank:]]*//;s/[[:blank:]]*$//')
	DATASTORE=$(echo "${DATASTORE#*/vmfs/volumes/}")
	DATASTORE_BACKUP="${VMFS_HEADER_BACKUP}/${DATASTORE}/${BACKUP_NAMING_CONVENTION}"
	
	mkdir -p ${DATASTORE_BACKUP}
	dd if=${VMFS_DEVICE:0:8} of=${DATASTORE_BACKUP}/vmfs-header-${VMFS_DEVICE:5:3}.hex bs=512 count=4096 > /dev/null 2>&1
	cp /vmfs/volumes/${UUID}/.vh.sf ${DATASTORE_BACKUP}/vmfs-metadata-${VMFS_DEVICE:5:3}-vh.sf.bu > /dev/null 2>&1
	
	#rotate backups
	checkBackupRotation "${VMFS_HEADER_BACKUP}/${DATASTORE}" "${DATASTORE_BACKUP}"
done

# remove temp file
rm "${VDF_OUTPUT}"

exit 0