1610s, "space for storing," from store (v.) + -age. Storage unit as a household piece attested from 1951.
Entries linking to storage
store v.
mid-13c., "to supply or stock," from Old French estorer "erect, construct, build; restore, repair; furnish, equip, provision," from Latin instaurare "to set up, establish; renew, restore," in Medieval Latin also "to provide, store," from in- "in" (from PIE root *en "in") + -staurare, from PIE *stau-ro-, suffixed extended form of root *sta- "to stand, make or be firm" (compare restore). The meaning "to keep in store for future use" (1550s) probably is a back-formation from store (n.). Related: Stored; storing.
-age
word-forming element in nouns of act, process, function, condition, from Old French and French -age, from Late Latin -aticum "belonging to, related to," originally neuter adjectival suffix, from PIE *-at- (source of Latin -atus, past participle suffix of verbs of the first conjugation) + *-(i)ko-, secondary suffix forming adjectives (see -ic).