On Wed, May 28, 2014 at 11:28:19AM -0600, Eric Blake wrote: > On 05/28/2014 09:14 AM, Alexander Binun wrote: > > [can you convince your mailer to wrap long lines?] > > > > > I have a program running on a VM guest. Its output is valuable (for VM introspection) so I want to let the host module know about it. I prefer to redirect ' stdio" of a guest into a device at the host (a text file or my device that has the name "mydev" > > and the driver is written for it). > > > > I have the XML definition file for my VM in /etc/libvirt/qemu. I have added the section: > > > > <serial type="file"> > > <source path="/var/log/vm/vml.log"/> > > <target port="0"/> > > </serial> > > > > into the /devices section. > > > > That is I want the stdio to be streamed into the file /var/log/vm/vml.log at the host. > > > > Then I run simple textual commands at the guest (ls, pwd and so on). > > How are you getting into your guest to run those commands? Did you > connect to your guest's serial console, or is it in a gui window, or via > an ssh session, or...? Are you sure the commands you are executing have > the guest's /dev/ttyS0 as their stdout? Your xml is correct and I think Eric's suggestion is right: if I put that <serial> snippet into a guest's XML and then echo "foo" > /dev/ttyS0 in the guest, I see "foo" in the host vml.log. > > But I do not see /var/log/vm/vml.log created at the host. > > I'm not sure whether libvirt will pre-create the file, or whether it > insists that the file already exists. Maybe others can chime in. I know > Dave Allan has done some work with python scripts that faithfully > capture all text output to the guest's serial console, although I don't > have a handy link to that sample script. The example script is consolecallback.py[1] but it really deals more with auto connecting to a serial console when a VM is booted than with doing anything special with the output, although it's useful if you have a VM going up and down and you want all its console output. Dave [1] http://libvirt.org/git/?p=libvirt-python.git;a=blob;f=examples/consolecallback.py;hb=HEAD > -- > Eric Blake eblake redhat com +1-919-301-3266 > Libvirt virtualization library http://libvirt.org > _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
