Thomas, >>> An idea is to allow the configuration of the behavior and add two >>> additional behaviors, >>> i.e. migrate away and relocate away. >> What's the difference between migration and relocation? Temporary vs. >> permanent? > > Migration does an online migration if possible (=on VMs) and the services is > already running. > Relocation *always* stops the service if it runs and only then migrates it. > If it then gets started on the other side again depends on the request state. > > The latter one may be useful on really big VMs where short down time can be > accepted > and online migration would need far to long or cause congestion on the > network.
Ah, ok. So relocation is migration without "online" checked (UI) or "qm migrate" without "--online"? >>>> (Please don't comment on whether this setup is ideal – I'm aware of the >>>> risks a single chassis brings…) >>> As long as nodes share continents your never save anyway :-P >> True, but impossible to implement for approx. 99.999999% of all PVE users. >> And latencies will be a nightmare then, esp. with >> Ceph :D > > Haha, yeah, would be quite a nightmare, if you haven't your own sea cable > connection :D Even then the latency adds up by approx. 1 millisecond per 100km… >>> Quasi, a maintenance mode? I'm not opposed to it, but if such a thing would >>> be done >>> it would be only a light wrapper around already existing functionality. >> Absolutely. Just another action that would evacuate the current host as >> optimal as possible. All VMs that are constrained to a >> specific node group should be migrated within that group, all other VMs >> should be migrated to any node available (possible doing >> some load balancing inside the cluster). > > I'll look again in this, if I get an idea how to incorporate this without > breaking edge cases I can give it a shot, > no promise yet, though, sorry :) >> If there are valid concerns against this reasoning, I'm open to suggestions >> for improvement. > > Sounds OK, I have to think about it if I can propose a better fitting > solution regarding our HA stack. > An idea was to add simple dependencies, i.e. this group/service should > not run on the same node as the other group/services. Not sure if this is > quite specialism or more people would profit from it... I'd like to hear you suggestions if you find the time… >> Interesting idea. Didn't have a look at priorities yet. >> >> Request for improvement: In "datacenter -> HA -> groups" show the configured >> priority, e.g. in a format >> "nodename(priority)[,nodename(priority)]" > > Hmm, this should already be the case, except if the default priority is set. > I added this when I reworked the HA group editor sometimes in 4.3. Well, I didn't play with priorities yet so it might be that it just didn't show up in my case. Thank you, Uwe _______________________________________________ pve-user mailing list pve-user@pve.proxmox.com https://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user