diff --git a/xCAT-server/share/xcat/install/scripts/pre.ubuntu b/xCAT-server/share/xcat/install/scripts/pre.ubuntu
index 96e26d7cf..aab441536 100644
--- a/xCAT-server/share/xcat/install/scripts/pre.ubuntu
+++ b/xCAT-server/share/xcat/install/scripts/pre.ubuntu
@@ -195,7 +195,7 @@ if [ -d /sys/firmware/efi ]; then
     echo "    ." >> /tmp/partitionfile
 else
     echo "ubuntu-boot ::" > /tmp/partitionfile
-    echo "100 50 100 ext3" >> /tmp/partitionfile
+    echo "256 256 512 ext3" >> /tmp/partitionfile
     echo '    $primary{ } $bootable{ } method{ format } format{ } use_filesystem{ } filesystem{ ext3 } mountpoint{ /boot }' >> /tmp/partitionfile
     echo "    ." >> /tmp/partitionfile
 fi
diff --git a/xCAT-server/share/xcat/install/scripts/pre.ubuntu.ppc64 b/xCAT-server/share/xcat/install/scripts/pre.ubuntu.ppc64
index f85210325..27bfb4f77 100644
--- a/xCAT-server/share/xcat/install/scripts/pre.ubuntu.ppc64
+++ b/xCAT-server/share/xcat/install/scripts/pre.ubuntu.ppc64
@@ -214,7 +214,7 @@ else
     echo '    $primary{ } $bootable{ } method{ prep }' >> /tmp/partitionfile
     echo "    ." >> /tmp/partitionfile
 
-    #echo "100 50 100 ext4" >> /tmp/partitionfile
+    #echo "256 256 512 ext4" >> /tmp/partitionfile
     #echo '    $primary{ } $bootable{ } method{ format } format{ } use_filesystem{ } filesystem{ ext4 } mountpoint{ /boot }' >> /tmp/partitionfile
     #echo "    ." >> /tmp/partitionfile
 fi