Installation guide

cgroup_device_acl = [
"/dev/null", "/dev/full", "/dev/zero",
"/dev/random", "/dev/urandom",
"/dev/ptmx", "/dev/kvm", "/dev/kqemu",
"/dev/rtc", "/dev/hpet", "/dev/net/tun",
4. Restart l i bvi rtd .
Important
Since each of these steps significantly decreases the host's security protections
against Q EMU guest domains, this configuration should only be used if there is no
alternative to using <i nterface type= 'ethernet' >.
Note
For more information on SELinux, refer to the Red Hat Enterprise Linux 6 Security-Enhanced Linux
User Guide.
B.13. Migrat ion fails wit h Erro r: unabl e to reso l ve ad d ress
Symp t o m
Q EMU guest migration fails and this error message appears:
# virsh migrate qemu qemu+tcp://192.168.122.12/system
error: Unable to resolve address name_of_host service '49155':
Name or service not known
For example, if the destination hostname is "newyork", the error message will appear as:
# virsh migrate qemu qemu+tcp://192.168.122.12/system
error: Unable to resolve address 'newyork' service '49155': Name
or service not known
However, this error looks strange as we did not use "newyork" hostname anywhere.
In vest ig at io n
During migration, lib virt d running on the destination host creates a URI from an address
and port where it expects to receive migration data and sends it back to lib virt d running
on the source host.
In this case, the destination host (19 2. 16 8. 122. 12) has its name set to 'newyork'. For
some reason, lib virt d running on that host is unable to resolve the name to an IP address
that could be sent back and still be useful. For this reason, it returned the 'newyork'
hostname hoping the source lib virt d would be more successful with resolving the name.
This can happen if DNS is not properly configured or /etc/ho sts has the hostname
associated with local loopback address (127. 0 . 0 . 1).
Common libvirt errors and t roublesh oot ing
14 5