Welcome to the oVirt MOM source repository. This repository is hosted on https://github.com/oVirt/mom.

MOM is a policy-driven tool that can be used to manage overcommitment on KVM hosts. Using a connection to the hypervisor software (either libvirt or oVirt vdsm), MOM keeps track of active virtual machines on a host. At a regular collection interval, data is gathered about the host and guests. Data can come from multiple sources (eg. the /proc interface, libvirt API calls, a client program connected to a guest, etc). Once collected, the data is organized for use by the policy evaluation engine. If configured, MOM regularly evaluates a user-supplied management policy using the collected data as input. In response to certain conditions, the policy may trigger reconfiguration of the system’s overcommitment mechanisms. Currently MOM supports control of memory ballooning and KSM but the architecture is designed to accommodate new mechanisms such as cgroups.

If MOM is not yet packaged for your Linux distribution it can beinstalled easily using the following sequence:

./autogen.sh
./configure
make
make install

To build an RPM using the included spec file you should first edit configure.ac to set RPM version information. You may want to set VERSION_SUFFIX to a string that will differentiate your builds from upstream builds. The '0.0' at the beginning of PACKAGE_RPM_RELEASE should be changed to '1' and should be incremented for each subsequent build of the same mom release. Once you have made the appropriate changes, execute the following commands to create an RPM:

rm *.tar.gz
./configure
make dist
rpmbuild -ta mom-*.tar.gz

By default, MOM looks for its configuration file in /etc/momd.conf. Before starting MOM for the first time, be sure to configure it. Sample configuration files can be found in the doc/ sub-directory of this distribution. The most important configuration settings are for the Hypervisor Interface, Collectors and Controllers.

MOM can run under two different hypervisor modes: vdsm and libvirt. If you are configuring a node running in an oVirt environment and are running vdsm on your node, you would select the vdsm HypervisorInterface. Otherwise, select libvirt to have MOM talk directly with libvirt.

Collectors determine what data is collected from the system and how. Controllers provide the tuning "knobs" that can be used by policies. The exact set of Collectors and Controllers you will need depends on the policies you want to use. You can find help for adjusting configuration settings by reading the comments included in the sample configuration files.

Once configured you can start MOM. Use your distribution's standard process if MOM has been packaged for it. Otherwise, start the MOM daemon (momd) yourself.

/usr/local/sbin/momd -c <config-file> -r <policy-file>

Example MOM configuration files and policies can be found in the doc/ subdirectory of this distribution.

Bugs can be reported in GitHub issues. For more detailed instruction see the oVirt documentation page.

MOM is part of the oVirt family of projects. For contact information including: IRC, mailing lists, and bugs, see: http://www.ovirt.org/community/