FWN/Beats/Virtualization

Virtualization

In this section, we cover discussion on the @et-mgmnt-tools-list, @fedora-xen-list, @libvirt-list and @ovirt-devel-list of Fedora virtualization technologies.

Contributing Writer: Dale Bewley

Enterprise Management Tools List

This section contains the discussion happening on the et-mgmt-tools list

Starting Guests from a Desktop Icon

Orion Poplawski said[1] "I'd like to provide an icon that would startup the virtual machine and connect to it." Cole Robinson posted[2] a couple of ways to accomplish this.

• With virt-manager and support for CDROM and USB devices

UUID=`virsh --connect qemu:///system domuuid vm-name`
virsh --connect qemu:///system start $UUID
virt-manager --connect qemu:///system \
             --show-domain-console=$UUID

• With virt-viewer which won't support CDROM and USB access

UUID=`virsh --connect qemu:///system domuuid vm-name`
virsh --connect qemu:///system start $UUID
virt-viewer --connect qemu:///system $UUID

Each solution requires adequate user permissions to work.

[1] https://www.redhat.com/archives/et-mgmt-tools/2008-October/msg00100.html

[2] https://www.redhat.com/archives/et-mgmt-tools/2008-October/msg00103.html

libvirt Plugins for Performance Monitoring Applications

Guido Günther announced[1] the creation of plugins[2] for net and block I/O monitoring in Munin[3].

Daniel Veillard posted[4] a patch to add this and similar plugins for collectd[5] and Nagios[6] to the libvirt applications page[7].

[1] https://www.redhat.com/archives/et-mgmt-tools/2008-October/msg00118.html

[2] http://munin.projects.linpro.no/

[3] http://honk.sigxcpu.org/projects/libvirt/monitor/

[4] https://www.redhat.com/archives/et-mgmt-tools/2008-October/msg00121.html

[5] http://collectd.org/plugins/libvirt.shtml

[6] http://et.redhat.com/~rjones/nagios-virt/

[7] http://libvirt.org/apps.html"

Fedora Xen List

This section contains the discussion happening on the fedora-xen list.

Libvirt List

This section contains the discussion happening on the libvir-list.

Openvz Bridge Support and Related Patches

Daniel Berrange posted[1] a patch series "derived from Anton Protopopov / Evgeniy Sokolov bridge device patches. It first does some generic refactoring of MAC address handler in all drivers, then adds code to extract OpenVZ[2] version number, then does network config, and finally does filesystem config."

[1] https://www.redhat.com/archives/libvir-list/2008-October/msg00323.html

[2] http://wiki.openvz.org/

Guest Image Locking

Itamar Heim asked[1] "how libvirt envisions image locking. i.e., how do we make sure multiple nodes are not trying to access the same storage volume".

Daniel Berrange said[2] in the domain XML format "the semantics are that every <disk> section added to a guest config is read-write, with an exclusive lock. To allow multiple guests to use the same disk, is intended that you add either <readonly/> or <sharable/> element within the <disk>."

Adding, "we only implement this for the Xen driver, handing off the actuall logic to XenD to perform. That we don't implement this in the QEMU driver is a clear shortcoming that needs addressing. "

The problem on a single host is relatively simple, but more complex among multiple host nodes. Guido Günther has been toying[3] "with the idea of using DLM[4] for libvirt".

[1] https://www.redhat.com/archives/libvir-list/2008-October/msg00334.html

[2] https://www.redhat.com/archives/libvir-list/2008-October/msg00336.html

[3] https://www.redhat.com/archives/libvir-list/2008-October/msg00342.html

[4] http://sources.redhat.com/cluster/dlm/

Exporting the Label on Block Devices

Chris Lalancette described[1] his patch "To support LVM partitioning in oVirt, one of the things we need is the ability to tell what kind of label is currently on a block device. Here, a 'label' is used in the same sense that it is used in parted; namely, it defines which kind of partition table is on the disk, whether it be DOS, LVM2, SUN, BSD, etc." Not the partition type.

[1] https://www.redhat.com/archives/libvir-list/2008-October/msg00341.html

Experimental User Mode Linux Driver

Daniel P. Berrange applied[1] a patch that "implements a driver supporting User Mode Linux[2] guests. User mode linux is a kind of paravirtualized kernel which runs on a plain Linux host. It requires no elevated privileges at all, except for some of the network integration. It is a pretty straightforward thing to invoke, so I figured it would be easy to write a driver to support it. I was right :-)"

[1] https://www.redhat.com/archives/libvir-list/2008-October/msg00355.html

[2] http://user-mode-linux.sourceforge.net/

oVirt Devel List

This section contains the discussion happening on the ovirt-devel list.