When in virt-manager you may find the path to the respective file in the configuration of the VM/disk (something like "source path"); default path is /var/lib/libvirt/images/
. Find out the name of the image of the virtual disk.
Let's say the image path is /var/lib/libvirt/images/disk1.qcow2
(I suppose qcow2 format here).
First, install libguestfs-tools
on the host:
sudo apt-get install libguestfs-tools
You can then mount the virtual disk by
sudo guestmount -a <image-file> -m <device> --ro /mnt
where <image-file>
means the full path to the disk image and <device>
the device name of the partition to mount. If you don't know the device name, you can give any name to list the valid devices, e.g.
sudo guestmount -a /var/lib/libvirt/images/disk1.qcow2 -m any --ro /mnt
This will give you something like
libguestfs: error: mount_options: mount_options_stub: any: expecting a device name
guestmount: 'any' could not be mounted.
guestmount: Did you mean to mount one of these filesystems?
guestmount: /dev/sda1 (ext2)
guestmount: /dev/sda2 (ext2)
To mount the first partition you have then to issue
sudo guestmount -a /var/lib/libvirt/images/disk1.qcow2 -m /dev/sda1 --ro /mnt
Now you can access the filesystem in read-only mode in /mnt.
Important: When mounting a disk of a running VM this way you must specify "--ro" which means read-only, otherwise the filesystem may be damaged.
Instead of using the name of the virtualdisk file you may enter the name of the virtual domain, if there are more than one disk. Let's say your virtual domain's name is myvm
, you may issue
sudo guestmount -d myvm -m any --ro /mnt
what will give you something like
guestmount: 'any' could not be mounted.
guestmount: Did you mean to mount one of these filesystems?
guestmount: /dev/sdb (iso9660)
guestmount: /dev/sda1 (ext4)
guestmount: /dev/sda2 (unknown)
guestmount: /dev/sda5 (swap)
guestmount: /dev/sdc1 (ext4)
guestmount: /dev/sdc2 (unknown)
guestmount: /dev/sdc5 (swap)
guestmount: /dev/sdd1 (ext2)
guestmount: /dev/sdd2 (ext2)
so now to mount /dev/sdc1 (seen from your VM's view) you can issue
sudo guestmount -d myvm -m /dev/sdc1 --ro /mnt
This should do the trick.
libguestfs
orqemu-nbd
, see How to mount qcow2 disk image