doc: documented how to mount a qcow2 image

README.md

@@ -303,3 +303,41 @@ Finally, I ran `mkfs.ext4`
 to create an ext4 file system
 in the encrypted partition.
 
+
+# mount qcow2 VM disk images
+
+This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords,
+edit files, or recover something without the virtual machine running.
+
+**Step 1 - Enable NBD on the Host**
+    
+```
+modprobe nbd max_part=8
+```
+
+**Step 2 - Connect the QCOW2 as network block device**
+
+```
+qemu-nbd --connect=/dev/nbd0 /var/lib/vz/images/100/vm-100-disk-1.qcow2
+```
+
+**Step 3 - Find The Virtual Machine Partitions**
+
+```
+fdisk /dev/nbd0 -l
+```
+
+**Step 4 - Mount the partition from the VM**
+
+```
+mount /dev/nbd0p1 /mnt
+```
+
+**Step 5 - After you are done, unmount and disconnect**
+
+```
+umount /mnt/somepoint/
+qemu-nbd --disconnect /dev/nbd0
+rmmod nbd
+```
+