Knowledge Base

Mounting qcow2 files to host filesystem

Converting to raw and mounting

kpartx does not work very well with qcow2 files. You can convert the qcow2 file to a raw file:

oldfile=file.qcow2
newfile=file.raw
qemu-img convert "${oldfile}" "${newfile}"

You can now find the partitions and map them:

kpartx -av "${newfile}"
mount /dev/loop2p2 /mnt/foo

Modifying a virtual machine to use the new image file

You can modify a virtual machine definition to use this new file:

virsh dumpxml ${domain} > domain.xml
vi domain.xml # Lines “source file=/path/file.raw” and “driver name=qemu type=raw"
virsh create domain.xml

Mounting lvm logical volumes from the image file

Update lvm with the currently attached disks.

pvscan; lvscan; lvdisplay

Now you can mount /dev/mapper/cl_centos7--02a_root to a mount point.

References

Weblinks

1. Converting qcow2 file to raw to make it work with kpartx https://www.certdepot.net/rhel7-access-virtual-machines-console/#comment-41448
2. An alternate way to mount a qcow2 file http://ask.xmodulo.com/mount-qcow2-disk-image-linux.html

Man pages

1. virsh