How to mount a QCOW2 image
Step 1
Login as root on the UCS host where the image can be accessed
Step 2
Enable network block device (NBD) on the Host
modprobe nbd max_part=8
Step 3
Connect the QCOW2 as network block device
qemu-nbd --connect=/dev/nbd0 /var/lib/vz/images/100/vm-100-disk-1.qcow2
Step 4
Find the Virtual Machine partitions
root@ucskvm:~# fdisk -l /dev/nbd0
Disk /dev/nbd0: 20 GiB, 21474836480 bytes, 41943040 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x000c820f
Device Boot Start End Sectors Size Id Type
/dev/nbd0p1 * 63 41929649 41929587 20G 83 Linux
Step 5
Activate the partition device nodes
partx -a /dev/nbd0
Step 6
Mount the partition from the VM
mount /dev/nbd0p1 /mnt/somepoint/
Step 7
After you are done, unmount and disconnect
umount /mnt/somepoint/
qemu-nbd --disconnect /dev/nbd0
rmmod nbd