Ah, it looks like I need to the MTU on the underlying vnet interface therefore should be able to extend the hook to include <mtu size="9000"/>. Have tried to add an additional property using: CustomDeviceProperties='{type=interface;prop={extnet_ovs=^[a-zA-Z0-9_ ---]+(:[a-zA-Z0-9_ ---]+|)$};{extnet_mtu=^[a-zA-Z0-9_ ---]+(:[a-zA-Z0-9_ ---]+|)$}};' but it fails with the following error: Cannot set value {type=interface;prop={extnet_ovs=^[a-zA-Z0-9_ ---]+(:[a-zA-Z0-9_ ---]+|)$};{extnet_mtu=^[a-zA-Z0-9_ ---]+(:[a-zA-Z0-9_ ---]+|)$}}; to key CustomDeviceProperties. Invalid syntax, custom device properties specification should conform to \{type=(disk|interface|video|sound|controller|balloon|channel|redir|console|rng|smartcard|watchdog);prop=\{((([a-z_A-Z0-9])+)=(([^;])*)(;(([a-z_A-Z0-9])+)=(([^;])*))*;?)?\}\}[;]? I did try: CustomDeviceProperties='{type=interface;prop={extnet_ovs=^[a-zA-Z0-9_ ---]+(:[a-zA-Z0-9_ ---]+|)$};prop={extnet_mtu=^[a-zA-Z0-9_ ---]+(:[a-zA-Z0-9_ ---]+|)$}};' but that just gave me a new property of 'prop' :) Any help appreciated please. Thanks, Phil ----- Original Message ----- From: "Phil Daws" <uxbod@splatnix.net> To: "Dan Yasny" <dyasny@gmail.com> Cc: "users" <users@ovirt.org> Sent: Friday, 21 November, 2014 8:49:51 AM Subject: Re: [ovirt-users] Jumbo Frames Hello Dan: We are using OVS for SFlow and OSPF functionality. You can see that the bridge was correctly set: ovirtmgmt: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 9000 Very odd as OVS is unaware of whether its jumbo frames or not. Thanks, Phil ----- Original Message ----- From: "Dan Yasny" <dyasny@gmail.com> To: "Phil Daws" <uxbod@splatnix.net> Cc: "users" <users@ovirt.org> Sent: Friday, 21 November, 2014 1:39:32 AM Subject: Re: [ovirt-users] Jumbo Frames Why do you use OVS at all? If you have VLANs, all you need is to tag the mgmt traffic, and create a VM traffic VLAN with a different MTU. The bridge and underlying NICs will have MTU=9000 and the VM bridge will have MTU=1500 On Thu, Nov 20, 2014 at 7:40 PM, Phil Daws < uxbod@splatnix.net > wrote: Hello: am really enjoying oVirt but have now hit an issue with iSCSI. As there is only one NIC in the host I have had to enable an MTU of 9000 on ovirtmgmt. Then have vNIC profiles on that interface which are using a custom hook for Openvswitch. I have created a specific vLAN for iSCSI traffic and on the initiator and targets have set their respective interface MTUs to be 9000. When I connect to a LUN it is timing out straight away with a 1011 error. If I drop the MTU back to 1500 all works okay. This is all fine on my other KVM, non-oVirt, system so am wondering if I have missed a step ? Thanks, Phil _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users