On 6/29/20 11:01 AM, Paul O'Rorke wrote: > Hi all, > > I couldn't find any documentation on this, hopefully someone can > point me in the right direction. > > I recently set up a sand-boxed environment for our developers. There > are domain controller(s), workstations and servers in there.  The > whole thing is running on a single host using a "Virtual Network" > defined in virt-manager on that host. > > Now I find I want to add more guests and there are not enough > resources on this one host.  Can I somehow make this Virtual Network > available to two hosts?  I do not want to move to a bridged network > and have to physically join the two hosts with a discrete link when > they are already on the same subnet at the host level. > > Is that possible? You might be able to this using OpenvSwitch (iow "probably can, but I don't know the details" :-)) but libvirt doesn't have anything to set it up for you; you would need to create and configure the OVS switch outside of libvirt, then attach the libvirt guests to that switch (using "<interface type='bridge'> ... <virtualport type='openvswitch'> ...") I've idly thought about having this as a libvirt feature over the years, but as I never have that many guests, it was never a personal priority, and it wasn't immediately clear what was the best way to handle, e.g. DHCP, and routing to the outside. Definitely "patches are welcome" though :-)

On 6/29/20 12:43 PM, Paul O'Rorke wrote: > Thanks Laine, > > I will take a look at Open vSwitch, it looks interesting. > > I am a generalist, I need to know enough about a lot of things to get > many different tasks done, but do not have the in depth knowledge > required to "patch" anything.  If I manage to wrangle a working > solution should I post it? Even a list of the steps you took to implement it manuall external to libvirt would be useful. Maybe that would inspire someone else to add support in libvirt virtual networks. We used to put stuff like that in the wiki, but I think the preferred location has changed / is changing and I'm not sure at the moment what the new norm is. > > Needless to say I would be supportive of said feature being > implemented by those more competent than I... > > Jocularity aside, thanks for the heads up on Open vSwitch. > > *Paul O'Rorke* > > > On 2020-06-29 9:13 a.m., Laine Stump wrote: >> On 6/29/20 11:01 AM, Paul O'Rorke wrote: >>> Hi all, >>> >>> I couldn't find any documentation on this, hopefully someone can >>> point me in the right direction. >>> >>> I recently set up a sand-boxed environment for our developers. >>> There are domain controller(s), workstations and servers in there.  >>> The whole thing is running on a single host using a "Virtual >>> Network" defined in virt-manager on that host. >>> >>> Now I find I want to add more guests and there are not enough >>> resources on this one host.  Can I somehow make this Virtual >>> Network available to two hosts?  I do not want to move to a bridged >>> network and have to physically join the two hosts with a discrete >>> link when they are already on the same subnet at the host level. >>> >>> Is that possible? >> >> You might be able to this using OpenvSwitch (iow "probably can, but >> I don't know the details" :-)) but libvirt doesn't have anything to >> set it up for you; you would need to create and configure the OVS >> switch outside of libvirt, then attach the libvirt guests to that >> switch (using "<interface type='bridge'> ... <virtualport >> type='openvswitch'> ...") >> >> I've idly thought about having this as a libvirt feature over the >> years, but as I never have that many guests, it was never a personal >> priority, and it wasn't immediately clear what was the best way to >> handle, e.g. DHCP, and routing to the outside. Definitely "patches >> are welcome" though :-) >>

Paul, if you can set up a VLAN on your network infrastructure between the two hosts, I'll share the recipe I use with Open VSwitch.  We trunk a VLAN between our hosts for sandboxed guests, setting up a OVS bridge on each host that handles guests but also has a connection onto the VLAN.  Are you using any configuration tool?  I've got this in Puppet but should be able to convert to a shell script. Cheers, - Peter On Mon, 29 Jun 2020 at 17:45, Paul O'Rorke <paul(a)tracker-software.com <mailto:paul@tracker-software.com>> wrote: Thanks Laine, I will take a look at Open vSwitch, it looks interesting. I am a generalist, I need to know enough about a lot of things to get many different tasks done, but do not have the in depth knowledge required to "patch" anything.  If I manage to wrangle a working solution should I post it? Needless to say I would be supportive of said feature being implemented by those more competent than I... Jocularity aside, thanks for the heads up on Open vSwitch. *Paul O'Rorke* On 2020-06-29 9:13 a.m., Laine Stump wrote: > On 6/29/20 11:01 AM, Paul O'Rorke wrote: >> Hi all, >> >> I couldn't find any documentation on this, hopefully someone can >> point me in the right direction. >> >> I recently set up a sand-boxed environment for our developers. >> There are domain controller(s), workstations and servers in >> there.  The whole thing is running on a single host using a >> "Virtual Network" defined in virt-manager on that host. >> >> Now I find I want to add more guests and there are not enough >> resources on this one host.  Can I somehow make this Virtual >> Network available to two hosts?  I do not want to move to a >> bridged network and have to physically join the two hosts with a >> discrete link when they are already on the same subnet at the >> host level. >> >> Is that possible? > > You might be able to this using OpenvSwitch (iow "probably can, > but I don't know the details" :-)) but libvirt doesn't have > anything to set it up for you; you would need to create and > configure the OVS switch outside of libvirt, then attach the > libvirt guests to that switch (using "<interface type='bridge'> > ... <virtualport type='openvswitch'> ...") > > I've idly thought about having this as a libvirt feature over the > years, but as I never have that many guests, it was never a > personal priority, and it wasn't immediately clear what was the > best way to handle, e.g. DHCP, and routing to the outside. > Definitely "patches are welcome" though :-) >