Terabyte drive is not officially supported, but may work, if it is a single drive in a box. Some terabyte drives and larger incorporate multiple 500GB or larger drives in an enclosure - these will NOT work.
Be EXTREMELY careful when switching or even removing the EHD from a 211, if it is still writing to the EHD it will corrupt the drive and it may not be easily reconnected.
I recommend you put the 211 in standby, then unplug it, then you may safely disconnect the EHD (hopefully).
I also recommend you reconnect the EHD before powering up the 211.
I have had 2 drives corrupted trying to disconnect or change them on my 211. It is a PITA to get them reconnected and if you finally succeed ann recordings are lost on the corrupted drive.