I'm trying to setup ESXi 5.0 with iSCSI so we can utilise MPIO, however i'm coming up against a problem. It's when i enable jumbo frames on the network adapters on the DSS.

The DSS has been factory reset and im starting from scratch.
I have setup 2 adapters for the storage on 2 different ip ranges.
I have enabled jumbo frames in the 2 switches that the adapters are connected to.
I have also enabled jumbo frames on the VMkernel adapters on ESXi.

Now this is where it goes wrong.

If i leave the MTU at 1500 for both adapters on the DSS i can scan the HBA and mount / access the iSCSI datastore no problem.
I can reboot the ESXi host and it boots in a timely fashion (with a v small delay on loading the iscsi portion of the kernel).

Now if i set the MTU of the adapters to 9000 on the DSS it takes forever to scan the HBA (about 7mins). It does finally show the target.
When i come to try and add it and format it, it just hangs and hangs detecting current disk layout just saying Loading...
Then errors with the following:
Code:
Call "HostDatastoreSystem.QueryVmfsDatastoreCreateOptions" for object "datastoreSystem-2594" on vCenter Server "VMWARE-VCS" failed.
Now if i drop the MTU on the DSS back down to 1500 everything works perfectly!!

This is really annoying me. Any ideas??