diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9e9dd79..c5a4e66 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ Record of the modification in project development.
 ## [Unreleased] - yyyy-mm-dd
 ### Added
 - [Issue 31 : Add extra partition functionality.](https://github.com/suikan4github/kaiten-yaki/issues/31)
+- [Issue 35 : Support "M/G/T" as size prefix.](https://github.com/suikan4github/kaiten-yaki/issues/35)
 
 ### Changed
 ### Deprecated
diff --git a/script/config.sh b/script/config.sh
index 096c64b..a4b0e8e 100644
--- a/script/config.sh
+++ b/script/config.sh
@@ -32,27 +32,35 @@ export LVEXT1SUFFIX="_home"
 export USELVEXT2=0
 export LVEXT2SUFFIX="_var"
 
-# Logical volume size of the Linux installation.
-# 30% mean, new logical volume will use 30% of the free space 
-# in the LVM volume group. For example, assume the free space is 100GB, 
-# and LVROOTSIZE is 30%FREE. Script will create 30GB logical volume.  
+
+# Volume size parameters. 
 # Note that the order of the volume creation is : 
 # 1. EFI if needed
 # 2. SWAP
 # 3. LVROOT
 # 4. LVEXT1 if needed
 # 5. LVEXT2 if needed
-export LVROOTSIZE="10%FREE"
-
-# Logical volume size of the optional volumes. 
-export LVEXT1SIZE="90%FREE"
-export LVEXT2SIZE="100%FREE"
 
 # Set the size of EFI partition and swap partition. 
 # The unit is Byte. You can use M,G... notation.
+# You CANNOT use the % notation. 
 export EFISIZE="200M"
+
+# Logical volume size of the swap volumes. 
 export LVSWAPSIZE="8G"
 
+# Logical volume size of the Linux installation.
+# There are four posibble way to specify the volume. 
+# nnnM, nnnG, nnnT : Absolute size speicification. nnnMbyte, nnnGByte, nnnT byte.  
+# mm%VG : Use mm% of the entire volume group. 
+# mm%FREE : Use mm% of the avairable storage are in the volume group. 
+export LVROOTSIZE="10G"
+
+# Logical volume size of the optional volumes. 
+export LVEXT1SIZE="30G"
+export LVEXT2SIZE="10G"
+
+
 # Usually, these names can be left untouched. 
 # If you change, keep them consistent through all installation in your system.
 export CRYPTPARTNAME="luks_volume"
diff --git a/script/lib/common.sh b/script/lib/common.sh
index c2a26e0..c37b0f9 100644
--- a/script/lib/common.sh
+++ b/script/lib/common.sh
@@ -141,6 +141,25 @@ function confirmation(){
 		return 1 # with error status
 	fi	# passphrase validation
 
+	
+	# Add -l or -L parameter to the size. The lvcreate command have two size parameter. 
+	# -l ###%[FREE|VG|PVS|ORIGIN] : Size by relative value. 
+	# -L ###[M|G|T|m|g|t] : Size by absolute value. 
+	# Too preven the duplicated match, awk exists the process after it match the /%/ pattern. 
+	# If Unit is not specified, installation will fail. 
+
+	LVSWAPSIZE=$(echo "${LVSWAPSIZE}" | awk '/%/{print "-l", $0; exit} /M|G|T|m|g|t/{print "-L", $0}')
+	export LVSWAPSIZE	
+	
+	LVROOTSIZE=$(echo "${LVROOTSIZE}" | awk '/%/{print "-l", $0; exit} /M|G|T|m|g|t/{print "-L", $0}')
+	export LVROOTSIZE
+
+	LVEXT1SIZE=$(echo "${LVEXT1SIZE}" | awk '/%/{print "-l", $0; exit} /M|G|T|m|g|t/{print "-L", $0}')
+	export LVEXT1SIZE
+
+	LVEXT2SIZE=$(echo "${LVEXT2SIZE}" | awk '/%/{print "-l", $0; exit} /M|G|T|m|g|t/{print "-L", $0}')
+	export LVEXT2SIZE
+
 	# succesfull return
 	return 0
 }
@@ -239,7 +258,8 @@ function pre_install() {
 		echo "...Swap volume already exist. Skipped to create. No problem."
 	else
 		echo "...Creating logical volume \"${LVSWAPNAME}\" on \"${VGNAME}\"."
-		lvcreate -L "${LVSWAPSIZE}" -n "${LVSWAPNAME}" "${VGNAME}" 
+		# Too use the bash IFS, first parameter is not quoted.  
+		lvcreate ${LVSWAPSIZE} -n "${LVSWAPNAME}" "${VGNAME}" 
 		if [ $? -ne 0 ] ; then deactivate_and_close; return 1 ; fi;
 	fi	# if /dev/mapper/swap volume already exit. 
 
@@ -272,7 +292,8 @@ function pre_install() {
 			return 1 # with error status
 		else # not exist and not overwrite install
 			echo "...Creating logical volume \"${LVROOTNAME}\" on \"${VGNAME}\"."
-			lvcreate -l "${LVROOTSIZE}" -n "${LVROOTNAME}" "${VGNAME}"
+			# Too use the bash IFS, first parameter is not quoted.  
+			lvcreate ${LVROOTSIZE} -n "${LVROOTNAME}" "${VGNAME}"
 			if [ $? -ne 0 ] ; then deactivate_and_close; return 1 ; fi;
 			IS_ROOT_CREATED=1
 
@@ -474,7 +495,8 @@ function create_ext_lv() {
 			echo "...Logical volume \"${VGNAME}-${LVROOTNAME}${LVEXT1SUFFIX}\" already exists. OK."
 		else
 			echo "...Creating logical volume \"${LVROOTNAME}${LVEXT1SUFFIX}\" on \"${VGNAME}\"."
-			lvcreate -l "${LVEXT1SIZE}" -n "${LVROOTNAME}${LVEXT1SUFFIX}" "${VGNAME}"
+			# Too use the bash IFS, first parameter is not quoted.  
+			lvcreate  ${LVEXT1SIZE} -n "${LVROOTNAME}${LVEXT1SUFFIX}" "${VGNAME}"
 			if [ $? -ne 0 ] ; then 	# if fail
 				echo "***** ERROR : failed to create "${VGNAME}-${LVROOTNAME}${LVEXT1SUFFIX}" . *****"
 				return 1 ; 
@@ -489,7 +511,8 @@ function create_ext_lv() {
 			echo "...Logical volume \"${VGNAME}-${LVROOTNAME}${LVEXT2SUFFIX}\" already exists. OK."
 		else
 			echo "...Creating logical volume \"${LVROOTNAME}${LVEXT2SUFFIX}\" on \"${VGNAME}\"."
-			lvcreate -l "${LVEXT2SIZE}" -n "${LVROOTNAME}${LVEXT2SUFFIX}" "${VGNAME}"
+			# Too use the bash IFS, first parameter is not quoted.  
+			lvcreate ${LVEXT2SIZE} -n "${LVROOTNAME}${LVEXT2SUFFIX}" "${VGNAME}"
 			if [ $? -ne 0 ] ; then 	# if fail
 				echo "***** ERROR : failed to create "${VGNAME}-${LVROOTNAME}${LVEXT1SUFFIX}" . *****"
 				return 1 ;