diff --git a/xCAT-server/share/xcat/install/scripts/getinstdisk b/xCAT-server/share/xcat/install/scripts/getinstdisk
index 6f6c85037..5520ab43b 100644
--- a/xCAT-server/share/xcat/install/scripts/getinstdisk
+++ b/xCAT-server/share/xcat/install/scripts/getinstdisk
@@ -24,6 +24,8 @@ mkdir -p $tmpdir
 
 has_awk=$(find / -name "awk")
 
+utolcmd="sed -e y/ABCDEFGHIJKLMNOPQRSTUVWXYZ/abcdefghijklmnopqrstuvwxyz/"
+
 tmpfile=$tmpdir"/getinstalldisk_"
 
 if [ -z "$install_disk" ]; then
@@ -42,9 +44,9 @@ if [ -z "$install_disk" ]; then
     # Classify entries by DEVTYPE
     for entry in $entries; do
         if [ -z "$has_awk" ]; then
-            dev_type=$(udevadm info --query=property --name=/dev/$entry | grep -i "DEVTYPE" | cut -d "=" -f2 | tr A-Z a-z)
+            dev_type=$(udevadm info --query=property --name=/dev/$entry | grep -i "DEVTYPE" | cut -d "=" -f2 | $utolcmd)
         else
-            dev_type=$(udevadm info --query=property --name=/dev/$entry | grep -i "DEVTYPE" | awk -F = '{print $2}' | tr A-Z a-z)
+            dev_type=$(udevadm info --query=property --name=/dev/$entry | grep -i "DEVTYPE" | awk -F = '{print $2}' | $utolcmd)
         fi        
  
         if [ "$dev_type" == "disk" ]; then
@@ -129,10 +131,12 @@ if [ -z "$install_disk" ]; then
     for disk in $disks; do
         # Get disk's information: WWN, PATH and DRIVER
         disk_info=$(udevadm info --query=property --name=$disk)
-        disk_wwn=$(IFS= ;echo $disk_info | grep '\<ID_WWN\>' | cut -d "=" -f2 | tr A-Z a-z)
-        disk_path=$(IFS= ;echo $disk_info | grep DEVPATH | cut -d "=" -f2 | tr A-Z a-z)
+        output_for_wwn=$(echo $disk_info | grep '\<ID_WWN\>' | cut -d "=" -f2 | $utolcmd)
+        disk_wwn=$(IFS= ;echo $output_for_wwn)
+        output_for_path=$(echo $disk_info | grep DEVPATH | cut -d "=" -f2 | $utolcmd)
+        disk_path=$(IFS= ;echo $output_for_path)
         disk_driver=$(udevadm info --attribute-walk --name=$disk | grep DRIVERS| grep -v '""'| grep -v '"sd"'|
-                    \head -n 1| sed -e 's/[^"]*"//' -e 's/"//' | tr A-Z a-z)
+                    \head -n 1| sed -e 's/[^"]*"//' -e 's/"//' | $utolcmd)
 
         echo "[get_install_disk]The disk $disk information: "
         echo "[get_install_disk]    disk_wwn=$disk_wwn"
diff --git a/xCAT-server/share/xcat/install/scripts/pre.rh b/xCAT-server/share/xcat/install/scripts/pre.rh
index 5eb3e8a77..2d798cbc0 100644
--- a/xCAT-server/share/xcat/install/scripts/pre.rh
+++ b/xCAT-server/share/xcat/install/scripts/pre.rh
@@ -184,45 +184,11 @@ fi
 #also, find first available block device (sda or vda likely)
 #TODO: pick a likely non-SAN target if possible
 shopt -s nullglob
-for disk in /dev/vd*[^0-9];do
-	if [ -z "$firstdirectdisk" ]; then firstdirectdisk=$disk; fi #remember first disk as a guess of medium resort
-	eddname=$(/lib/udev/edd_id $disk 2> /dev/null)
-	if [ ! -z "$eddname" -a "$eddname" = "int13_dev80" ]; then
-		instdisk=$disk
-		break
-	fi
-done
 
-if [ -z "$instdisk" ]; then
-	for disk in /dev/sd*[^0-9]; do
-		eddname=$(/lib/udev/edd_id $disk 2> /dev/null)
-		if [ ! -z "$eddname" -a "$eddname" = "int13_dev80" ]; then
-			instdisk=$disk
-			break
-		fi
-		currdriver=`udevadm info --attribute-walk --name $disk |grep DRIVERS|grep -v '""'|grep -v '"sd"'|head -n 1|sed -e 's/[^"]*"//' -e 's/"//'`
-		case "$currdriver" in 
-		"ata_piix4"|"PMC MaxRAID"|"ahci"|"megaraid_sas") #certainly direct
-			if [ -z "$firstdirectdisk" ]; then firstdirectdisk=$disk; fi #remember first disk as a guess of medium resort
-			;;
-		"mptsas"|"mpt2sas"|"mpt3sas") #*PROBABLY* not SAN, but SAS SAN is possible
-			if [ -z "$probablyfirstdirectdisk" ]; then probablyfirstdirectdisk=$disk; fi #remember first disk as a guess of medium resort
-			;;
-		*)
-			if [ -z "$firstdisk" ]; then firstdisk=$disk; fi #remember first disk as a guess of medium resort
-			;;
-		esac
-	done
-fi
-
-if [ -z "$instdisk" ]; then
-	if [ ! -z "$firstdirectdisk" ]; then 
-		instdisk=$firstdirectdisk 
-	elif [ ! -z "$probablyfirstdirectdisk" ]; then
-		instdisk=$probablyfirstdirectdisk 
-	elif [ ! -z "$firstdisk" ]; then
-		instdisk=$firstdisk 
-	fi
+#The script getinstdisk is common for rh/sles/pkvm/ubuntu, it will write the install_disk into /tmp/install_disk file
+#INCLUDE:#ENV:XCATROOT#/share/xcat/install/scripts/getinstdisk#
+if [ -e "/tmp/install_disk" ]; then
+    instdisk=`cat /tmp/install_disk`
 fi
 
 # Could not determine the install disk for whatever reason,