diff --git a/xCAT-server/share/xcat/install/ubuntu/compute.tmpl b/xCAT-server/share/xcat/install/ubuntu/compute.tmpl
index adcfab038..f867ecb45 100644
--- a/xCAT-server/share/xcat/install/ubuntu/compute.tmpl
+++ b/xCAT-server/share/xcat/install/ubuntu/compute.tmpl
@@ -38,9 +38,24 @@ d-i partman-md/device_remove_md boolean true
 #create the /tmp/partitioning based on the uefi or legacy bios 
 d-i partman/early_command string \
     set -x; \
-    DEV=`ls /dev/disk/by-path/* -l | egrep -o '/dev.*sd[^0-9]$' | sort -t : -k 1 -k 2 -k 3 -k 4 -k 5 -k 6 -k 7 -k 8 -g | head -n1 | egrep -o 'sd.*$'`; \
-    if [[ $DEV == "" ]]; then DEV="sda"; fi; \
-    echo "/dev/$DEV" > /tmp/boot_disk; \
+    rm /tmp/devs-with-grub 2>/dev/null || true; \
+    for d in $(list-devices partition); do \
+        mkdir -p /tmp/mymount; \
+        rc=0; \
+        mount $d /tmp/mymount || rc=$?; \
+        if [[ $rc -eq 0 ]]; then \
+            [[ -e /tmp/mymount/grub/grub.cfg ]] && echo $d >>/tmp/devs-with-grub; \
+            umount /tmp/mymount; \
+        fi \
+    done; \
+    if [[ -e /tmp/devs-with-grub ]]; then \
+        head -n1 /tmp/devs-with-grub | egrep  -o '\S+[^0-9]' > /tmp/boot_disk; \
+        rm /tmp/devs-with-grub 2>/dev/null || true; \
+    else \
+        DEV=`ls /dev/disk/by-path/* -l | egrep -o '/dev.*sd[^0-9]$' | sort -t : -k 1 -k 2 -k 3 -k 4 -k 5 -k 6 -k 7 -k 8 -g | head -n1 | egrep -o 'sd.*$'`; \
+        if [[ $DEV == "" ]]; then DEV="sda"; fi; \
+        echo "/dev/$DEV" > /tmp/boot_disk; \
+    fi; \
     debconf-set partman-auto/disk "$(cat /tmp/boot_disk)"
 d-i partman-auto/expert_recipe_file string /tmp/partitioning