Complete control is odd around large storage area (12)
I believe the answer is:
stranglehold
'complete control' is the definition.
(having a stranglehold means having total control)
'odd around large storage area' is the wordplay.
'odd' becomes 'strange' (I've seen this in another clue).
'around' is an insertion indicator.
'large' becomes 'L' (eg in clothes sizes).
'storage area' becomes 'hold' (synonyms).
'strange' enclosing 'l' is 'strangle'.
'strangle'+'hold'='STRANGLEHOLD'
'is' is the link.
(Other definitions for stranglehold that I've seen before include "Complete power over a situation" , "Complete control" , "Total restriction" , "Star long held (anag) - complete power over a person" , "Inexorable grip" .)