On Mon, Nov 07, 2016 at 11:53:20AM +0000, Guy Plunkett wrote: >> On 7 Nov 2016, at 11:50, Kevin Lemonnier <[email protected]> wrote: >> >>> moving the /etc/pve/nodes/pve11/qemu-server/*.conf files to another node >>> worked well. I didn't have to restart any services. >> >> Still, that seems like a fairly usual operation that the GUI could >> very well support, I think. >> Would it be possible to add that in the future ? >it would also be nice for the GUI not to lose the details of the VMs if the >node is down, and indeed allow the transfer of the VM to an active node. > >I know this can be done today with the HA but it would be nice to also do this >for non HA VMs
the problem is that PVE has a notion of nodes being owners of their respective ressources (like containers or VMs). the technical background is that we only allow changes to their configuration in processes holding a node-local lock, to prevent race conditions and conflicts. cluster-wide locking is very expensive, and is thus only used when absolutely needed (like allocating/freeing disk images on shared storage). a consequence of this architectural design is that node A cannot "steal" a VM/container (or rather, its configuration file) from another node B, because there is no way for a process on node A to lock this file (only node B is able and allowed to locally lock and modify it). the only exception to this is for HA-managed ressources, because our HA stack has a system of cluster-wide locking and watchdogs to ensure that it only steals ressources from actually dead nodes (and in a conflict-free manner). so there are only three options: - use HA for automatic migration on node failure - move the configuration files manually as root when a node has died, and take the blame if you moved from a node that was not actually dead (in which case you violated one of the basic assumptions of PVE and "anything" might happen) - change this architectural design (not likely, as it is one of the basic principles of PVE's clustering ;)) I hope this makes it clear why this case is handled like it is, and that it's not some arbitrary unwillingness to add this functionality to the API/GUI ;) p.s. top-posting makes email threads rather hard to follow, please consider switching to in-line replies or bottom-posting _______________________________________________ pve-user mailing list [email protected] http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-user
