On Fri, Oct 30, 2020 at 8:14 PM Strahil Nikolov <[email protected]> wrote:
> If you mean "Administration" -> "Providers" -> "Ovirt-provider-ovn" -> it > is enabled. > > Yes, this one. If it is enabled, Engine should reflect the MTU which is provided by ovirt-provider-ovn via OpenStack API. The related configuration value dhcp-mtu of ovirt-provider-ovn is explained in https://github.com/oVirt/ovirt-provider-ovn/blob/master/README.adoc. > Best Regards, > Strahil Nikolov > > > > > > > В петък, 30 октомври 2020 г., 21:10:02 Гринуич+2, Strahil Nikolov < > [email protected]> написа: > > > > > > Any hint for the location of "Automatic Synchronization" in UI ? > > Best Regards, > Strahil Nikolov > > > > > > > В петък, 30 октомври 2020 г., 20:16:13 Гринуич+2, Dominik Holler < > [email protected]> написа: > > > > > > > > On Fri, Oct 30, 2020 at 7:03 PM Strahil Nikolov <[email protected]> > wrote: > > in 4.3.10's UI it shows 1500 :) > > > > This might be just a misleading representation of the default value or an > unknown value. > If "Automatic Synchronization" is enabled for the ovirt-provider-ovn in > oVirt Engine, > the value should be updated in Engine to the correct after the next > synchronization in the background. > > > > > > > > > > > > > В петък, 30 октомври 2020 г., 13:25:05 Гринуич+2, Dominik Holler < > [email protected]> написа: > > > > > > > > > > > > > > > > On Thu, Oct 29, 2020 at 9:36 PM Alex K <[email protected]> wrote: > >> > >> > >> On Tue, Oct 27, 2020, 02:49 Strahil Nikolov via Users <[email protected]> > wrote: > >>> Hello All, > >>> > >>> I would like to learn more about OVN and especially the maximum MTU > that I can use in my environment. > >>> > >>> Current Setup 4.3.10 > >>> Network was created via UI -> MTU Custom -> 8976 -> Create on External > Provider -> Connect to Physical Network > >>> > >>> So my physical connection is MTU 9000 and I have read that Geneve uses > 24 bits (maybe that's wrong ?) , thus I have reduced the MTU to 8976. > >> From the internet draft it seems that the tunnel header + reserved bits > comprise 64 bits. A common practice for Geneve implementations is to use > 8900 mtu for VMs when having 9000 mtu physical network. > >> > > > > Ack, this is a safe choice. > > In oVirt's default configuration, an overhead of 58 bytes > > ( = 20 IPv4 header + 8 UDP header + 16 GENEVE Ethernet header (including > 8 bytes options) + 14 bytes inner Ethernet header) > > is added. > > This is why the default MTU for OVN networks in oVirt is 1442 bytes, > which assumes 1500 bytes MTU in the physical network. > > > > > > > >> > >> The draft: > >> https://tools.ietf.org/html/draft-ietf-nvo3-geneve-08 > >>> > >>> I did some testing on the VMs and ping with payload of '8914' was the > maximum I could pass without fragmenting and thus the MTU on the VMs was > set to 8942. > >>> > >>> Did I correctly configure the test network's MTU and am I > understanding it correctly that we need extra 34 bits inside the network > for encapsulation ? > >>> > > > > You could check with packet analyzers like tcpdump and wireshark. > > > >>> I have checked > https://www.ovirt.org/develop/release-management/features/network/managed_mtu_for_vm_networks.html > but I don't see any refference how to calculate the max MTU. > >>> > >>> > >>> Best Regards, > >>> Strahil Nikolov > >>> _______________________________________________ > >>> Users mailing list -- [email protected] > >>> To unsubscribe send an email to [email protected] > >>> Privacy Statement: https://www.ovirt.org/privacy-policy.html > >>> oVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/ > >>> List Archives: > https://lists.ovirt.org/archives/list/[email protected]/message/CKNS5T5KE2W5EIXBTGQDU3URKHQDVAM4/ > >>> > >>> > >> _______________________________________________ > >> Users mailing list -- [email protected] > >> To unsubscribe send an email to [email protected] > >> Privacy Statement: https://www.ovirt.org/privacy-policy.html > >> oVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/ > >> List Archives: > >> > https://lists.ovirt.org/archives/list/[email protected]/message/VIDP3MLYHWG2WXQ6JB6EHK66J5WBOMVT/ > >> > >> > > _______________________________________________ > > Users mailing list -- [email protected] > > To unsubscribe send an email to [email protected] > > Privacy Statement: https://www.ovirt.org/privacy-policy.html > > oVirt Code of Conduct: > https://www.ovirt.org/community/about/community-guidelines/ > > List Archives: > > > https://lists.ovirt.org/archives/list/[email protected]/message/7UN5DXXKXN3KBLTLGXIPTGWVF4ODKKUB/ > > > > > >
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