Provided by: debvm_0.3.1_all 
NAME
debvm-run - Run a VM image created by debvm-create
SYNOPSIS
debvm-run [-g] [-i image] [-s sshport] [-- qemu options]
DESCRIPTION
debvm-run is essentially a thin wrapper around qemu for running a virtual machine image created by debvm-
create or something compatible. The virtual machine image is expected to be a raw ext4 image with a non-
empty file system label. The architecture of the machine is detected from the contained /bin/true. It
must contain a symbolic link pointing to a kernel image at one of (|/boot)/vmlinu[xz] a symbolic link
pointing to an initrd image at initrd.img in the same directory as the kernel image. Both are extracted
and passed to qemu. A net interface configured for user mode is added automatically.
OPTIONS
--append=cmdline
While the kernel command line can be modified by passing -append to qemu directly, doing that
always replaces the entire command line and thus removes important values passed by debvm-run.
This variant instead appends given command line arguments to the automatic ones. Repeated use
also causes appending rather than replacement.
-g, --graphical
By default, the option -nographic is passed to qemu and one interacts with the serial console of
the machine. This configuration is skipped in the presence of this option. Note that debvm-
create defaults to installing a cloud kernel if available, so you may have to pass
"--include=linux-image-generic" during image construction to get graphics drivers.
-i image, --image=image
This option specifies the location of the virtual machine image file. By default rootfs.ext4 in
the working directory is used.
--netopt=option
debvm-run sets up a user mode network by default. It therefore passes a -netdev option to qemu.
Using this option, you can customize the value of that -netdev option. For instance, you can set
up additional port forwards by passing e.g. "--netopt hostfwd=:127.0.0.1:8080-:80". It can be
used multiple times.
--skip=task
Skip a particular task or feature. The option may be specified multiple times or list multiple
tasks to be skipped by separating them with a comma. By default, no tasks are skipped. The
following tasks may be skipped.
--transport=transport
When debvm adds devices to qemu, it has to select a transport and it most often guesses pci.
When specifying a different machine such as -machine microvm, a different transport such as
device may be needed.
network
Do not configure a network card. Use this if you want to configure network on your own.
This should also be passed in addition to passing "-nic none" when you want to disable
networking.
rngdev
Do not pass a random number generator device.
root
Skip all of the following tasks matching "root/*". If either of these is present, the VM
will not boot unless a suitable replacement is added in another way.
root/cmd
Since debvm-run uses qemu as bootloader it normally passes the label of the root block device
via the kernel command line. This passing can be inhibited to supply a different location.
root/dev
A block device for the root filesystem is no longer passed. This can be used to customize
the block device.
-s sshport, --sshport=sshport
If given, qemu is configured to pass connections to 127.0.0.1:sshport to port 22 of the virtual
machine. You can connect to your virtual machine without updating your known hosts like this:
ssh -o NoHostAuthenticationForLocalhost=yes -p $sshport root@127.0.0.1
The option is a shorthand for "--netopt hostfwd=tcp:127.0.0.1:sshport-:22".
-- qemu options
All options beyond a double dash are passed to qemu. This can be used to configure additional
hardware components. One possible use of this method is passing -snapshot to avoid modifying the
virtual machine image.
EXAMPLES
Run a virtual machine stored in the image rootfs.ext4 (the default) with local port 8022 routed to port
22 of the virtual machine. The -snapshot argument is passed to QEMU and prevents any permanent changes to
rootfs.ext4, resulting in an ephemeral run.
debvm-run -s 8022 -i rootfs.ext4 -- -snapshot
FAQ
The debvm-run console renders wrong.
Make sure $TERM is set to a value known inside the VM. You may need to install ncurses-term for
more definitions. The serial console will miss events of resizing the terminal emulator. You
may run "setterm --resize" in that case.
How can I kill debvm-run?
The wrapped qemu can be terminated by pressing Ctrl-a x. Refer to the qemu manual page for more
escape sequences.
LIMITATIONS
Due to the way kernel and bootloader are being extracted before running qemu, one cannot upgrade a kernel
and then just reboot. Attempting to do so, will still use the old kernel. Instead, qemu must be
terminated and debvm-run should be launched again to pick up the new kernel. In order to avoid
accidental reboots, one may pass -no-reboot to qemu.
For 32bit arm, highmem is actively disabled, because the default kernel flavour fails to boot. If you
want to pass more ram, please also pass -machine virt and install a lpae kernel. Alternatively, use an
arm64 kernel.
SEE ALSO
debvm-create(1) qemu(1)