On 08/03/2017 10:47 AM, Cedric Bosdonnat wrote: > On Thu, 2017-08-03 at 10:05 -0400, Cole Robinson wrote: >> On 07/24/2017 04:04 AM, Cedric Bosdonnat wrote: >>> Hi all, >>> >>> While working on a special VM setup here, I was wondering about introducing >>> some configuration templates in virt-manager. >>> >>> We could have a drop down list somewhere in the UI to select a template. Here >>> is a list of possible templates we could propose: >>> >>> * 'Full host VM' >>> expose as much as possible of the host to a single VM >>> no migration possible >>> * 'Easily migratable VM' >>> * 'normal-sized VM, as fast as possible' >>> no migration possible either >>> >>> Obviously choosing one of these templates would be optional. That drop down >>> list could be in the final page of the new guest wizard. >>> >>> Any opinion on such a feature? >>> >> >> Sorry for the late response. >> >> Besides <cpu> setting, what types of features do you see tweaking for 'Full >> host' vs 'easily' vs 'normal'? > > In the full host, we would have the cpu model passed through, but also cpu pinning, > vNUMA setup and IOThreads. We could also define the memory hugepage size if applicable > and disable THP. > > Easily migratable VM for example would get basic cpu features. We could use cpu-baseline > and cpu-compare to get the user define (in the preferences) a set of minimal cpu features > among his hosts. > >> If the main differentiator is 'how migratable is this VM' I don't like the >> idea of putting that into the New VM wizard, since I think 99% of virt-manager >> users don't care about that, and migration is a difficult concept with a lot >> of VM config caveats, plus it usually requires host configuration outside of >> virt-manager to get working so it's unlikely to be something that 'just works'. > > Having it in the configuration doesn't help users discovering such a new feature. Discoverability has a tradeoff though. If it's an obvious self describing feature that many people will want to use and can't live without, make it 100% discoverable. But anything that isn't relevant to many users, and/or has drawbacks for some users, or is difficult to explain? Putting it in the New VM wizard means ever user may have to ask themselves a question (migratable vs full host vs middle ground) they might not know the answer to. These are the things I try to consider when adjusting the New VM wizard and other highly visible parts of the UI > And for people wanting a full-host VM, that would be more interesting in the VM setup, > since they may not want this for all their hosts managed by virt-manager... > Or we could have this defined in the connection (thinking out loud). > >> However I'm more open to a kind of migration vs performance setting in the >> Preferences dialog that determines the default New VM setup. But to discuss >> that we should start with a list of features you see enabling/disabling > > I'll try to come up with some precise profiles then. > Cool, thanks. The important thing with those performance features is to understand if they have tradeoffs. Migratability is the obvious one, but are there performance tradeoffs or are they always wins A UI starting point might be to add an option to the details cpu or memory page to sync settings with host topology or something like that. - Cole _______________________________________________ virt-tools-list mailing list virt-tools-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/virt-tools-list
