On Wed, Nov 23, 2016 at 2:59 PM, Arik Hadas <[email protected]> wrote: > Hi All, > > We are working on something that is expected to have a big impact, hence this > heads-up. > First, we want you to be aware of this change and provide your feedback to > make it as good as possible. > Second, until the proposed mechanism is fully merged there will be a chase to > cover all features unless new features are also implemented with the new > mechanism. So please, if you are working on something that adds/changes > something in the Libvirt's domain xml, do it with this new mechanism as well > (first version would be merged soon). > > * Goal > Creating Libvirt XML in the engine rather than in VDSM. > ** Today's flow > Engine: VM business entity -> VM properties map > VDSM: VM properties map -> Libvirt XML > ** Desired flow > Engine: VM business entity -> Libvirt XML > > * Potential Benefits > 1. Reduce the number of conversions from 2 to 1, reducing chances for > mistakes in the process. > 2. Reduce the amount of code in VDSM. > 3. Make VM related changes easier - today many of these changes need to be > reviewed in 2 projects, this will eliminate the one that tends to take longer. > 4. Prevent shortcuts in the form of VDSM-only changes that should be better > reflected in the engine. > 5. Not to re-generate the XML on each rerun attempt of VM run/migration. > 6. Future - not to re-generate the XML on each attempt to auto-start HA VM > when using vm-leases (need to make sure we're using the up-to-date VM > configuration though). > 7. We already found improvements and cleanups that could be made while > touching this area (e.g., remove the boot order from devices in the database). > > * Challenges > 1. Not to move host-specific information to the engine. For example, path to > storage domain or sockets of channels. > The solution is to use place-holders that will be replaced by VDSM. > 2. Backward compatibility. > 3. The more challenging part is the other direction - that will be the next > phase. > > * Status > As a first step, we began with producing the Libvirt XML in the engine by > converting the VM properties map to XML in the engine [1] > And using the XML that is received as an input in VDSM [2]
Thanks for the heads up! How does this, if at all, affect: 1. vdsm hooks 2. The interaction of engine, hosted-engine HA agent, engine vm configuration saved in shared storage, etc.? Will this require a change in ha-agent and the saved configuration? Best, > > > [1] https://gerrit.ovirt.org/#/c/64473/ > [2] https://gerrit.ovirt.org/#/c/65182/ > > Regards, > Arik > _______________________________________________ > Devel mailing list > [email protected] > http://lists.ovirt.org/mailman/listinfo/devel -- Didi _______________________________________________ Devel mailing list [email protected] http://lists.ovirt.org/mailman/listinfo/devel
