One way is to set the interfaces on the vm's to use dhcp.
The ovn dhcp is set to use the maximum allowed mtu value (1442 if host nic
mtu is 1500).
Another option would be to increase the host mtu all network devices
outside the vm to be bigger by 58 than the vm mtu.
The difference is caused by the tunneling overhead on each packet.
On Tue, May 8, 2018 at 7:11 PM, Samuli Heinonen <samppah(a)neutraali.net>
wrote:
Thanks Marcin! I set MTU to 1400 and connections seem to work. I
haven't
experienced any disconnects so far.
Is there any other way to set MTU rather than setting it per VM? Ie.
setting it on oVirt/OVN side.
-samuli
Marcin Mirecki wrote:
> Could you try the following:
> on the vms, lower the mtu of the vnics connected to the ovn network?
> And try again?
>
>
> On Tue, May 8, 2018 at 11:40 AM, Samuli Heinonen<samppah(a)neutraali.net>
> wrote:
>
> Hi Marcin,
>>
>> Here is ip addr output from virtual machines:
>>
>> [root@testi2 ~]# ip addr
>> 1: lo:<LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen
>> 1
>> link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>> inet 127.0.0.1/8 scope host lo
>> valid_lft forever preferred_lft forever
>> inet6 ::1/128 scope host
>> valid_lft forever preferred_lft forever
>> 2: eth0:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
>> state UP qlen 1000
>> link/ether 00:1a:4a:16:01:05 brd ff:ff:ff:ff:ff:ff
>> inet 10.0.1.25/24 brd 10.0.1.255 scope global dynamic eth0
>> valid_lft 86331sec preferred_lft 86331sec
>> inet6 fe80::21a:4aff:fe16:105/64 scope link
>> valid_lft forever preferred_lft forever
>> 3: eth2:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
>> state UP qlen 1000
>> link/ether 00:1a:4a:16:01:03 brd ff:ff:ff:ff:ff:ff
>> inet 10.0.200.10/24 brd 10.0.200.255 scope global dynamic eth2
>> valid_lft 86334sec preferred_lft 86334sec
>> inet6 fe80::21a:4aff:fe16:103/64 scope link
>> valid_lft forever preferred_lft forever
>>
>> eth0 connected to network ovirtmgmt
>> eth2 connected to OVN network vm-public
>>
>> [root@testi6 ~]# ip addr
>> 1: lo:<LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen
>> 1
>> link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>> inet 127.0.0.1/8 scope host lo
>> valid_lft forever preferred_lft forever
>> inet6 ::1/128 scope host
>> valid_lft forever preferred_lft forever
>> 2: eth0:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
>> state UP qlen 1000
>> link/ether 00:1a:4a:16:01:0b brd ff:ff:ff:ff:ff:ff
>> inet 10.0.1.27/24 brd 10.0.1.255 scope global dynamic eth0
>> valid_lft 86187sec preferred_lft 86187sec
>> inet6 fe80::21a:4aff:fe16:10b/64 scope link
>> valid_lft forever preferred_lft forever
>> 3: eth1:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
>> state UP qlen 1000
>> link/ether 00:1a:4a:16:01:0c brd ff:ff:ff:ff:ff:ff
>> inet 10.0.200.11/24 brd 10.0.200.255 scope global dynamic eth1
>> valid_lft 86301sec preferred_lft 86301sec
>> inet6 fe80::21a:4aff:fe16:10c/64 scope link
>> valid_lft forever preferred_lft forever
>>
>> eth0 connected to network ovirtmgmt
>> eth1 connected to OVN network vm-public
>>
>> Best regards,
>> Samuli
>>
>>
>>
>> Marcin Mirecki kirjoitti 08.05.2018 10:14:
>>
>> Hi Samuli,
>>>
>>> Your configuration looks correct.
>>> Can you also send me the result of 'ip addr' on your vm's?
>>>
>>> Thanks,
>>> Marcin
>>>
>>> On Mon, May 7, 2018 at 7:44 PM, Samuli Heinonen
>>> <samppah(a)neutraali.net> wrote:
>>>
>>> Hi Marcin,
>>>
>>>> Thank you for your response.
>>>>
>>>> I used engine-setup to do the configuration. Only exception is that
>>>> I had to run "vdsm-tool ovn-config engine-ip local-ip" (ie.
>>>> vdsm-tool ovn-config 10.0.1.101 10.0.1.21) on hypervisors.
>>>>
>>>> Here is the output of requested commands:
>>>>
>>>> [root@oe ~]# ovn-sbctl show
>>>> Chassis "049183d5-61b6-4b9c-bae3-c7b10d30f8cb"
>>>> hostname: "o2.hirundinidae.local"
>>>> Encap geneve
>>>> ip: "10.0.1.18"
>>>> options: {csum="true"}
>>>> Port_Binding "87c5e44a-7c8b-41b2-89a6-fa52f27643ed"
>>>> Chassis "972f1b7b-10de-4e4f-a5f9-f080890f087d"
>>>> hostname: "o3.hirundinidae.local"
>>>> Encap geneve
>>>> ip: "10.0.1.21"
>>>> options: {csum="true"}
>>>> Port_Binding "ccea5185-3efa-4d9c-9475-9e46009fea4f"
>>>> Port_Binding "e868219c-f16c-45c6-b7b1-72d044fee602"
>>>>
>>>> [root@oe ~]# ovn-nbctl show
>>>> switch 7d264a6c-ea48-4a6d-9663-5244102dc9bb (vm-private)
>>>> port 4ec3ecf6-d04a-406c-8354-c5e195ffde05
>>>> addresses: ["00:1a:4a:16:01:06 dynamic"]
>>>> switch 40aedb7d-b1c3-400e-9ddb-16bee3bb312a (vm-public)
>>>> port 87c5e44a-7c8b-41b2-89a6-fa52f27643ed
>>>> addresses: ["00:1a:4a:16:01:03"]
>>>> port ccea5185-3efa-4d9c-9475-9e46009fea4f
>>>> addresses: ["00:1a:4a:16:01:0c"]
>>>> port e868219c-f16c-45c6-b7b1-72d044fee602
>>>> addresses: ["00:1a:4a:16:01:0a"]
>>>>
>>>> [root@o2 ~]# ip addr
>>>> 1: lo:<LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state
UNKNOWN
>>>> qlen 1
>>>> link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>>>> inet 127.0.0.1/8 [1] scope host lo
>>>> valid_lft forever preferred_lft forever
>>>> inet6 ::1/128 scope host
>>>> valid_lft forever preferred_lft forever
>>>> 2: enp0s31f6:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovirtmgmt state UP qlen 1000
>>>> link/ether 78:f2:9e:90:bc:64 brd ff:ff:ff:ff:ff:ff
>>>> 3: enp0s20f0u5c2:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master public state UNKNOWN qlen 1000
>>>> link/ether 50:3e:aa:4c:9b:01 brd ff:ff:ff:ff:ff:ff
>>>> 4: ovs-system:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state
DOWN
>>>> qlen 1000
>>>> link/ether 82:49:e1:15:af:56 brd ff:ff:ff:ff:ff:ff
>>>> 5: br-int:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
qlen
>>>> 1000
>>>> link/ether a2:bb:78:7e:35:4b brd ff:ff:ff:ff:ff:ff
>>>> 21: public:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
noqueue
>>>> state UP qlen 1000
>>>> link/ether 50:3e:aa:4c:9b:01 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::523e:aaff:fe4c:9b01/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 22: ovirtmgmt:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> noqueue state UP qlen 1000
>>>> link/ether 78:f2:9e:90:bc:64 brd ff:ff:ff:ff:ff:ff
>>>> inet 10.0.1.18/24 [2] brd 10.0.1.255 scope global ovirtmgmt
>>>>
>>>> valid_lft forever preferred_lft forever
>>>> inet6 fe80::7af2:9eff:fe90:bc64/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 23: genev_sys_6081:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65000
>>>> qdisc noqueue master ovs-system state UNKNOWN qlen 1000
>>>> link/ether 02:c0:7a:e3:4e:76 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::c0:7aff:fee3:4e76/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 24: ;vdsmdummy;:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state
>>>> DOWN qlen 1000
>>>> link/ether a2:2f:f2:58:88:da brd ff:ff:ff:ff:ff:ff
>>>> 26: vnet0:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovs-system state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:03 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:103/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 29: vnet1:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovirtmgmt state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:05 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:105/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>>
>>>> [root@o2 ~]# ovs-vsctl show
>>>> 6be6d37c-74cf-485e-9957-f8eb4bddb2ca
>>>> Bridge br-int
>>>> fail_mode: secure
>>>> Port br-int
>>>> Interface br-int
>>>> type: internal
>>>> Port "ovn-972f1b-0"
>>>> Interface "ovn-972f1b-0"
>>>> type: geneve
>>>> options: {csum="true", key=flow,
>>>> remote_ip="10.0.1.21"}
>>>> Port "vnet0"
>>>> Interface "vnet0"
>>>> ovs_version: "2.9.0"
>>>>
>>>> [root@o3 ~]# ip addr
>>>> 1: lo:<LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state
UNKNOWN
>>>> qlen 1
>>>> link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>>>> inet 127.0.0.1/8 [1] scope host lo
>>>> valid_lft forever preferred_lft forever
>>>> inet6 ::1/128 scope host
>>>> valid_lft forever preferred_lft forever
>>>> 2: enp0s31f6:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovirtmgmt state UP qlen 1000
>>>> link/ether 78:f2:9e:90:bc:50 brd ff:ff:ff:ff:ff:ff
>>>> 3: enp0s20f0u5c2:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master public state UNKNOWN qlen 1000
>>>> link/ether 50:3e:aa:4c:9c:03 brd ff:ff:ff:ff:ff:ff
>>>> 4: ovs-system:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state
DOWN
>>>> qlen 1000
>>>> link/ether 7e:43:c1:b0:48:73 brd ff:ff:ff:ff:ff:ff
>>>> 5: br-int:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
qlen
>>>> 1000
>>>> link/ether 3a:fe:68:34:31:4c brd ff:ff:ff:ff:ff:ff
>>>> 21: public:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
noqueue
>>>> state UP qlen 1000
>>>> link/ether 50:3e:aa:4c:9c:03 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::523e:aaff:fe4c:9c03/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 22: ovirtmgmt:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> noqueue state UP qlen 1000
>>>> link/ether 78:f2:9e:90:bc:50 brd ff:ff:ff:ff:ff:ff
>>>> inet 10.0.1.21/24 [3] brd 10.0.1.255 scope global ovirtmgmt
>>>>
>>>> valid_lft forever preferred_lft forever
>>>> inet6 fe80::7af2:9eff:fe90:bc50/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 24: ;vdsmdummy;:<BROADCAST,MULTICAST> mtu 1500 qdisc noop state
>>>> DOWN qlen 1000
>>>> link/ether 02:92:3f:89:f2:c7 brd ff:ff:ff:ff:ff:ff
>>>> 25: vnet0:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovirtmgmt state UNKNOWN qlen 1000
>>>> link/ether fe:16:3e:0b:b1:2d brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc16:3eff:fe0b:b12d/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 27: vnet2:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovirtmgmt state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:0b brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:10b/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 29: vnet4:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovs-system state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:0c brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:10c/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 31: vnet6:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovirtmgmt state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:07 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:107/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 32: vnet7:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master public state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:09 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:109/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 33: vnet8:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc
>>>> pfifo_fast master ovs-system state UNKNOWN qlen 1000
>>>> link/ether fe:1a:4a:16:01:0a brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::fc1a:4aff:fe16:10a/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>> 34: genev_sys_6081:<BROADCAST,MULTICAST,UP,LOWER_UP> mtu 65000
>>>> qdisc noqueue master ovs-system state UNKNOWN qlen 1000
>>>> link/ether 46:88:1c:22:6f:c3 brd ff:ff:ff:ff:ff:ff
>>>> inet6 fe80::4488:1cff:fe22:6fc3/64 scope link
>>>> valid_lft forever preferred_lft forever
>>>>
>>>> [root@o3 ~]# ovs-vsctl show
>>>> 8c2c19fc-d9e4-423d-afcb-f5ecff602ca7
>>>> Bridge br-int
>>>> fail_mode: secure
>>>> Port "vnet4"
>>>> Interface "vnet4"
>>>> Port "ovn-049183-0"
>>>> Interface "ovn-049183-0"
>>>> type: geneve
>>>> options: {csum="true", key=flow,
>>>> remote_ip="10.0.1.18"}
>>>> Port "vnet8"
>>>> Interface "vnet8"
>>>> Port br-int
>>>> Interface br-int
>>>> type: internal
>>>> ovs_version: "2.9.0"
>>>>
>>>> Best regards,
>>>> Samuli
>>>>
>>>> Marcin Mirecki wrote:
>>>>
>>>> Hi Samuli,
>>>>
>>>> Let's first make sure the configuration is correct.
>>>> How did you configure the env? Did you use the automatic
>>>> engine-setup
>>>> configuration?
>>>>
>>>> Can you please send me the output of the following:
>>>>
>>>> on engine:
>>>> ovn-sbctl show
>>>> ovn-nbctl show
>>>>
>>>> on hosts:
>>>> ip addr
>>>> ovs-vsctl show
>>>>
>>>> The 'vdsm-tool ovn-config' command configures the ovn controller
to
>>>> use the
>>>> first ip as the ovn central, and the local tunnel to use the second
>>>> one.
>>>>
>>>> Regards,
>>>> Marcin
>>>>
>>>> On Sun, May 6, 2018 at 10:42 AM, Samuli
>>>> Heinonen<samppah(a)neutraali.net>
>>>> wrote:
>>>>
>>>> Hi all,
>>>>
>>>> I'm building a home lab using oVirt+GlusterFS in hyperconverged(ish)
>>>> setup.
>>>>
>>>> My setup consists of 2x nodes with ASRock H110M-STX motherboard,
>>>> Intel
>>>> Pentium G4560 3,5 GHz CPU and 16 GB RAM. Motherboard has integrated
>>>> Intel
>>>> Gigabit I219V LAN. At the moment I'm using RaspberryPi as Gluster
>>>> arbiter
>>>> node. Nodes are connected to basic "desktop switch" without
any
>>>> management
>>>> available.
>>>>
>>>> Hardware is nowhere near perfect, but it get its job done and is
>>>> enough
>>>> for playing around. However I'm having problems getting OVN to work
>>>> properly and I'm clueless where to look next.
>>>>
>>>> oVirt is setup like this:
>>>> oVirt engine host oe / 10.0.1.101
>>>> oVirt hypervisor host o2 / 10.0.1.18
>>>> oVirt hypervisor host o3 / 10.0.1.21
>>>> OVN network 10.0.200.0/24 [4]
>>>>
>>>> When I spin up a VM in o2 and o3 with IP address in network
>>>> 10.0.1.0/24 [5]
>>>>
>>>> everything works fine. VMs can interact between each other without
>>>> any
>>>> problems.
>>>>
>>>> Problems show up when I try to use OVN based network between virtual
>>>> machines. If virtual machines are on same hypervisor then everything
>>>> seems
>>>> to work ok. But if I have virtual machine on hypervisor o2 and
>>>> another one
>>>> on hypervisor o3 then TCP connections doesn't work very well. UDP
>>>> seems to
>>>> be ok and it's possible to ping hosts, do dns& ntp queries and
so
>>>> on.
>>>>
>>>> Problem with TCP is that for example when taking SSH connection to
>>>> another
>>>> host at some point connection just hangs and most of the time it's
>>>> not even
>>>> possible to even log in before connectiong hangs. If I look into
>>>> tcpdump at
>>>> that point it looks like packets never reach destination. Also, if I
>>>> have
>>>> multiple connections, then all of them hang at the same time.
>>>>
>>>> I have tried switching off tx checksum and other similar settings,
>>>> but it
>>>> didn't make any difference.
>>>>
>>>> I'm suspecting that hardware is not good enough. Before
>>>> investigating into
>>>> new hardware I'd like to get some confirmation that everything is
>>>> setup
>>>> correctly.
>>>>
>>>> When setting up oVirt/OVN I had to run following undocumented
>>>> command to
>>>> get it working at all: vdsm-tool ovn-config 10.0.1.101 10.0.1.21
>>>> (oVirt
>>>> engine IP, hypervisor IP). Especially this makes me think that I
>>>> have
>>>> missed some crucial part in configuration.
>>>>
>>>> On oVirt engine in /var/log/openvswitch/ovsdb-server-nb.log there
>>>> are
>>>> error messages:
>>>> 2018-05-06T08:30:05.418Z|00913|stream_ssl|WARN|SSL_read: unexpected
>>>> SSL
>>>> connection close
>>>> 2018-05-06T08:30:05.418Z|00914|jsonrpc|WARN|ssl:127.0.0.1:53152 [6]:
>>>> receive
>>>> error: Protocol error
>>>> 2018-05-06T08:30:05.419Z|00915|reconnect|WARN|ssl:127.0.0.1:53152
>>>> [6]:
>>>> connection dropped (Protocol error)
>>>>
>>>> To be honest, I'm not sure what's causing those error messages
or
>>>> are they
>>>> related. I found out some bug reports stating that they are not
>>>> critical.
>>>>
>>>> Any ideas what to do next or should I just get better hardware? :)
>>>>
>>>> Best regards,
>>>> Samuli Heinonen
>>>> _______________________________________________
>>>> Users mailing list
>>>> Users(a)ovirt.org
>>>>
http://lists.ovirt.org/mailman/listinfo/users [7]
>>>>
>>>>
>>>
>>> Links:
>>> ------
>>> [1]
http://127.0.0.1/8
>>> [2]
http://10.0.1.18/24
>>> [3]
http://10.0.1.21/24
>>> [4]
http://10.0.200.0/24
>>> [5]
http://10.0.1.0/24
>>> [6]
http://127.0.0.1:53152
>>> [7]
http://lists.ovirt.org/mailman/listinfo/users
>>>
>>>
>