When upgrading Dell Force10 switches, keep in mind that starting from FTOS version 9.10, MTU per port can no longer be set to 12000. It is now limited to a maximum of 9216, making it the same maximum as the DNOS (Dell Networking) firmware. After the firmware update, the MTU of each port will automatically be adjusted.

For jumbo frames, this doesn't really change anything. An MTU 9216 on the switch still results in a datagram MTU of 9000, sufficient for e.g. Equallogic storage.