diff --git a/xCAT-server/share/xcat/install/scripts/getinstdisk b/xCAT-server/share/xcat/install/scripts/getinstdisk
index 8752f7663..a5cabb2b1 100644
--- a/xCAT-server/share/xcat/install/scripts/getinstdisk
+++ b/xCAT-server/share/xcat/install/scripts/getinstdisk
@@ -13,7 +13,7 @@
 #    type, select the first one.
 # 3. Select the default one: /dev/sda.
 #
-# Output: /tmp/xcat.install_disk
+# Output: Install disk name written to /tmp/xcat.install_disk
 #
 #-----------------------------------------------------------
 
@@ -31,7 +31,7 @@ tmpfile="$tmpdir/getinstalldisk_"
 
 if [ -z "$install_disk" ]; then
 
-    echo "[get_install_disk]Information from /proc/partitions:"
+    echo "[get_install_disk]Contents of /proc/partitions:"
     cat /proc/partitions
     echo ""
 
@@ -67,6 +67,7 @@ if [ -z "$install_disk" ]; then
     mkdir -p $mount_dir;
 
     disk_array=""
+    umount_rc=0
 
     for partition in $partitions; do
         echo "[get_install_disk]Check the partition $partition."
@@ -107,7 +108,13 @@ if [ -z "$install_disk" ]; then
             # It seems the kernel file in ubuntu and sles are named like vmlinux, but in RH it is called vmlinuz
             # To check both vmlinux and vmlinuz, use regular expression "vmlinu*" to match them
             for i in $ker_dir/vmlinu*; do
-                disk_part=${partition%%[0-9]*}
+                if [[ $partition = nvme* ]]; then
+                    # Expected nvme partition format example: nvme0n1p1
+                    disk_part=${partition%%p*}
+                else
+                    # Expected sd partition format example: sda1
+                    disk_part=${partition%%[0-9]*}
+                fi
                 touch "$tmpfile$disk_part"
                 disk_array=$disk_array"$disk_part "
                 echo "[get_install_disk]    The partition $partition has kernel file."
@@ -115,6 +122,10 @@ if [ -z "$install_disk" ]; then
             done
 
             umount -l $mount_dir || echo "[get_install_disk]    $partition umount failed."
+            if [ $? -ne 0 ]; then
+                # Preserve a umount failure RC
+                umount_rc=$?
+            fi
         else
             echo "[get_install_disk]    Partition $partition mount failed or the partition is swap."
         fi
@@ -128,7 +139,13 @@ if [ -z "$install_disk" ]; then
         echo ""
     fi
 
-    rmdir $mount_dir;
+    if [ $umount_rc -eq 0 ]; then
+        rmdir $mount_dir;
+    else
+        # Do not remove $mount_dir if there was a umount failure, as it might wipe out
+        # the contents of a still mounted disk
+        echo "[get_install_disk]There was a umount failure earlier, not removing $mount_dir"
+    fi
 
     for file in $tmpfile*; do
         rm $file;
@@ -215,7 +232,7 @@ rm -rf $tmpdir;
 # Cannot find proper disk for OS install, select the default one "/dev/sda"
 if [ -z "$install_disk" ]; then
     install_disk="/dev/sda"
-    echo "[get_install_disk]The default install_disk is $install_disk."
+    echo "[get_install_disk]Choosing default install_disk is $install_disk."
 fi
 
 # Output the result to $install_disk_file