KVM virsh console

As a reminder, how to enable serial console under KVM.

Hypervisor (CentOS 7):
– no changes required if required pty -devices are created automatically (-chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 in guest command line)
–  if not found, you need the following bit in the devices section of virtual guests XML-file (modifying usually requires a full shutdown-start sequence for the virtual):

<serial type='pty'>
  <target port='0'/>
</serial>
<console type='pty'>
  <target type='serial' port='0'/>
</console>

Guest (Debian 7):
– modify /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet"
#GRUB_TERMINAL=console

->

GRUB_CMDLINE_LINUX_DEFAULT="console=ttyS0 quiet"
GRUB_TERMINAL=serial
GRUB_SERIAL_COMMAND="serial"

Uncomment the following line from /etc/inittab:

T0:23:respawn:/sbin/getty -L ttyS0 9600 vt100

Run update-grub and reboot virtual machine – now you should be able to use virsh console at the hypervisor.

<edit-16.1.2015>
– Added XML-configuration for serial/console
– Dropped 9600bps speed configuration
</edit>