Configuring jumbo frames

[sdewar83]

Hi,

we have recieved a MD3220i SAN and wanted to connect it up to one of our hosts

later on we'd like to turn on jumbo frames but unfortunately we havent recieved network switches yet which are capable of supporting jumbo frames and we're waiting on delivery of the switches.

Can i configure the host to speak to the San now and just run the cli commands to turn on jumbo frames and configure the switch for jumbo frames later on?  Or will this cause problems/headaches?

In the MD3220i Vmware whitepaper configuring jumbo frames is the first instruction - if configuring with out jumbo frames and then attempting to go back and reconfigure later will cause headaches i'd rather just wait another week until the switches come in.

Any advice would be appreciated!!

Sorry if this is posted in the wrong section of the forums --- i wasnt sure where to post

Regards

S

[11satya]

In the MD3220i Vmware whitepaper configuring jumbo frames is the first  instruction - if configuring with out jumbo frames and then attempting  to go back and reconfigure later will cause headaches i'd rather just  wait another week until the switches come in.

yes better follow the instruction .

_________________________________
Good luck!

[rickardnobel]

sdewar83 wrote:

Can i configure the host to speak to the San now and just run the cli commands to turn on jumbo frames and configure the switch for jumbo frames later on?  Or will this cause problems/headaches?

You should be able to setup everything now, even including enabling Jumbo frames on the SAN and the vSwitch, but do not enable it on the VMkernel interface in the host.

The host to SAN connection will use only ordinary frame sizes. Later when your new physical switches has arrived and been configured you could enable Jumbo on the VMkernel which would allow larger frame sizes on your storage network.

Do you have ESXi 4 or 5?

[AndreTheGiant]

With ESXi 5 you can configure all from vSphere Client.

First be sure that physical switches and MD3xxxi interfaces have Jumbo Frames enables, then increase the MTU in the vSwitch, then in the vmkernel interfaces for iSCSI.

[spf62]

We are having issues with Jumbo frames. Everything appears to be configured correctly yet nothing:

We have ESXi 5.0 on HP BL465c blades (this is our test ESXi enviroment),

Pro curve 2810-48g switches.

When I set the MTU ti anything higer than 1500, VMotion doesn't work at all.

We had our pro curve config blessed by Pro Curve support, but maybe they missed something.

Attached is our switch config

Can someone please point me in the right direction

[rickardnobel]

Could you describe the configuration steps you have taken on the ESXi hosts (vmkernel ports and vSwitches)?

[spf62]

On my VMotion (vkernal) switch, I have this config.

See attached

[rickardnobel]

Have you also changed the MTU on the vSwitch? Based on what you reported (vMotion stopped working after changing this and the Procurve configuration looks correct) I would say that it likely is what is missing.

[spf62]

Rickard,I did on my VMotion Vswitch, what other vswitches should I do this on?

[rickardnobel]

So you have set the MTU on the vMotion Vmkernel port, the vSwitch used for vMotion and for the correct VLAN on the physical switch? And done this on all ESXi hosts?

After done all steps, use vmkping with the correct parameters to test out that the larger MTU is available through the network.

[spf62]

Rickard, That worked. I had only set the VMKERNAL and not the VSWITCH.

Thank you very much, something so simple.

I didn't do vmkping yet. I just installed ESXi 5.0 and still trying to find out how to get to a putty session?

[rickardnobel]

Nice to see your problem resolved!

I didn't do vmkping yet. I just installed ESXi 5.0 and still trying to find out how to get to a putty session?

You have to enable the SSH service first, which is disabled by default. This could be done in various way, but the simplest may be to use the DCUI interface directly at the host console. Log in with F2, go to troubleshooting options and enable SSH.

[spf62]

Worked like a champ!! thanks again

[rickardnobel]

spf62 wrote:

Worked like a champ!! thanks again

Glad to be able to help.

regards / Rickard