Assail directors about quantity of computer data (7)
I believe the answer is:
bombard
'assail' is the definition.
(bombarding is a kind of assailing)
'directors about quantity of computer data' is the wordplay.
'directors' becomes 'board' (board of directors).
'about' is an insertion indicator.
'quantity of computer data' becomes 'mb' (I can't explain this - if you can you should give a lot more credence to this answer).
'board' going around 'mb' is 'BOMBARD'.
Can you help me to learn more?
(Other definitions for bombard that I've seen before include "Batter heavily and persistently" , "Organ stop" , "Attack with missiles" , "Pelt with missiles" , "Attack persistently" .)