To mount qcow2 virtual machine image, you need to install qemu-nbd.
On Ubuntu, run
apt-get install qemu-utils
Load the kernel module with command
modprobe nbd
For testing, we download Fedora 25 gcow2 image
wget https://download.fedoraproject.org/pub/fedora/linux/releases/26/CloudImages/x86_64/images/Fedora-Cloud-Base-26-1.5.x86_64.qcow2
Lets check the file details
root@server2:~# file Fedora-Cloud-Base-26-1.5.x86_64.qcow2 Fedora-Cloud-Base-26-1.5.x86_64.qcow2: QEMU QCOW Image (v2), 4294967296 bytes root@server2:~#
Lets mount it on device /dev/nbd0
qemu-nbd -c /dev/nbd0 Fedora-Cloud-Base-26-1.5.x86_64.qcow2
You need to find the device name, that will be something like /dev/nbd0xx, try all until you get it mounted.
root@backup:~# ls -l /dev/ | grep nb brw-rw---- 1 root disk 43, 0 Aug 23 03:25 nbd0 brw-rw---- 1 root disk 43, 1 Aug 23 03:25 nbd0p1 brw-rw---- 1 root disk 43, 16 Aug 23 03:24 nbd1 brw-rw---- 1 root disk 43, 160 Aug 23 03:24 nbd10 brw-rw---- 1 root disk 43, 176 Aug 23 03:24 nbd11 brw-rw---- 1 root disk 43, 192 Aug 23 03:24 nbd12 brw-rw---- 1 root disk 43, 208 Aug 23 03:24 nbd13 brw-rw---- 1 root disk 43, 224 Aug 23 03:24 nbd14 brw-rw---- 1 root disk 43, 240 Aug 23 03:24 nbd15 brw-rw---- 1 root disk 43, 32 Aug 23 03:24 nbd2 brw-rw---- 1 root disk 43, 48 Aug 23 03:24 nbd3 brw-rw---- 1 root disk 43, 64 Aug 23 03:24 nbd4 brw-rw---- 1 root disk 43, 80 Aug 23 03:24 nbd5 brw-rw---- 1 root disk 43, 96 Aug 23 03:24 nbd6 brw-rw---- 1 root disk 43, 112 Aug 23 03:24 nbd7 brw-rw---- 1 root disk 43, 128 Aug 23 03:24 nbd8 brw-rw---- 1 root disk 43, 144 Aug 23 03:24 nbd9 root@backup:~#
In our chase, it is nbd0p1
Let us mount it with
mount /dev/nbd0p1 /mnt
Now you will be able to see files in folder /mnt
If you are done with with image, you can unmount it with
umount /mnt
Lets remove the device mapping with
qemu-nbd -d /dev/nbd0
Example
root@server2:~# modprobe nbd root@server2:~# qemu-nbd -c /dev/nbd0 Fedora-Cloud-Base-26-1.5.x86_64.qcow2 root@server2:~# mount /dev/nbd0p1 /mnt root@server2:~# cd /mnt root@server2:/mnt# ls -la total 84 dr-xr-xr-x. 18 root root 4096 Jul 5 17:47 . drwxr-xr-x 22 root root 4096 Aug 23 03:57 .. lrwxrwxrwx. 1 root root 7 Feb 10 2017 bin -> usr/bin dr-xr-xr-x. 6 root root 4096 Jul 5 17:49 boot drwxr-xr-x. 2 root root 4096 Jul 5 17:45 dev drwxr-xr-x. 71 root root 4096 Jul 5 17:50 etc drwxr-xr-x. 2 root root 4096 Feb 10 2017 home lrwxrwxrwx. 1 root root 7 Feb 10 2017 lib -> usr/lib lrwxrwxrwx. 1 root root 9 Feb 10 2017 lib64 -> usr/lib64 drwx------. 2 root root 16384 Jul 5 17:45 lost+found drwxr-xr-x. 2 root root 4096 Feb 10 2017 media drwxr-xr-x. 2 root root 4096 Feb 10 2017 mnt drwxr-xr-x. 2 root root 4096 Feb 10 2017 opt drwxr-xr-x. 2 root root 4096 Jul 5 17:45 proc dr-xr-x---. 2 root root 4096 Jul 5 17:50 root drwxr-xr-x. 2 root root 4096 Jul 5 17:45 run lrwxrwxrwx. 1 root root 8 Feb 10 2017 sbin -> usr/sbin drwxr-xr-x. 2 root root 4096 Feb 10 2017 srv drwxr-xr-x. 2 root root 4096 Jul 5 17:45 sys drwxrwxrwt. 7 root root 4096 Jul 5 17:50 tmp drwxr-xr-x. 12 root root 4096 Jul 5 17:47 usr drwxr-xr-x. 19 root root 4096 Jul 5 17:47 var root@server2:/mnt# cd root@server2:~# umount /mnt root@server2:~# qemu-nbd -d /dev/nbd0 /dev/nbd0 disconnected root@server2:~#
