TechCenter Extras

TechCenter Extras
Dell Technical solutions information on various topics, hosted on the Dell TechCenter IT community platform

Equallogic iSCSI initiator and jumbo frames don't seem to work...

  • alas, pinging from the guest vm only goes up to 1475 size.
    any ping request after this failes. I'm going to try from scratch and hope everything works the second time around.
    thanks everyone.
  • ok changing vm nic to vxmnet3 worked. now I can ping with up to 9000 frame size to the group IP.
    thanks mellerbeck
  • Great! glad you got it to work!
  • "Hi,
    the two powerconnect switches are trunked with 10GbE link
    I've double checked the both swiches have jumbo frames enabled on the ports and also flow control enabled globaly. (that copy feature on the web interface to configure the switche ports doesn't really work) MTU is set to 9216.

    I will try the vmkping -9000 command to see what I get.
    If you are trunking, be sure that you have Jumbo Frames enabled on the TRUNK. While the ports that make up the trunk may have JF enabled, the trunk itself may not.

    What you may be seeing is that you get JF connection when your host to array connection does not need to traverse the trunk, but then the host-array connection may get redirected across the trunk at a future date and if the trunk does not have JF enabled, then you are reverting back to standard frames.

    Just a thought.




    Tony Ansley,Technical Marketing Consultant

    Dell Storage

  • "ok changing vm nic to vxmnet3 worked. now I can ping with up to 9000 frame size to the group IP.
    thanks mellerbeck"
    I was able to get this to work as well after using VMXNET3.

    We use Cisco 3750E switches. Inside the guest (Windows 2008 R2) the max ping size I could use was 8970. If I set it to 8975 or larger, it would not work.
  • Its specifically stated on VMware KB to use VMXNET3 for Jumbo Frames inside guest OS:

    This was also mentioned at the EQL Conference back in October. Check my blog for full coverage and best practices discussed at the conference.