Currently we do not have an option to format a target volume through DSS in GFS.
To change the MTU for Jumbo Frames:
From The console Press CTRL-ALT-W then select Tuning Options -> Jumbo Frames config then select the ethernet card that you want to change.
Please note: your network must be able to support jumbo frames as well.
I have seen instances where Jumbo frames and Bonding have been used at the same time