How to test Jumbo Frames on a vmkernel port

Here's an "Oldie but a Goodie".  I've been using it recently to sort out some iSCSI issues, so I figured I'd share.

The vmkping command sources a ping from a vmkernel port on the ESXi host.

-I - Allows you to specify a vmkernel port.

-d - Sets the Do Not Fragment bit on the packet.  This MUST be used to test Jumbo Frames.

-s - is the size of the payload.  

From the ESXi shell run the following command:

vmkping -I vmk1 -d -s 8972 x.x.x.x

In my case, I specified vmk1, which is used for the software iSCSI initiator.  x.x.x.x. was my storage array. 

The payload size must be set to 8972 due to the ICMP (8 bytes) and IP (20 bytes) header. .

Fix - Cisco UCS - Virtual Media redirection is already in use by another user

While performing an ESXi install on one of the Cisco UCS Blades, I received the following error:

I confirmed that no other users were using the UCS KVM, rebooted the blade from within the ESXi OS and through UCS Central etc.

To resolve this issues log into UCS Manger.  Then from the Equipment tab select the server exhibiting this behavior:

From the Servers General tab, select Recover Server and select Reset CIMC.  Resetting the CIMC will not cause a disruption of service.

That's it, I was then able to launch the KVM and attach Virtual Media.