ransack v.

"covered building for the storage of farm produce," Middle English bern, bærn, from Old English bereærn "barn," literally "barley house," from bere "barley" (see barley) + aern "house; place for storing," metathesized from *rann, *rasn (source also of Old Norse rann "large house," Gothic razn "house," Old English rest "resting place").

For the formation and the second element, compare saltern "a salt-works," from Old English sealtærn "saltworks;" Old English horsern "stable." Latin cellarium was glossed by Old English hordern, and dormitorium was slæpern.

In Anglo-Saxon England, barley was a primary grain crop:

Barley was not always the only crop grown as the data recovered at Bishopstone might suggest but it is always the most commonly represented, followed by wheat and then rye and oats. [C.J. Arnold, "An Archaeology of the Early Anglo-Saxon Kingdoms," 1988, p.36]

Another word for "barn" in Old English was beretun, "barley enclosure" (with tun "enclosure, house"), which accounts for the many Barton place names on the English map and the common surname.

It was applied from early 18c. to any large, barn-like building. Barn door has been used figuratively for "broad target" since 1670s and "great size" since 1540s. Barn-owl is attested by 1670s. Barn-raising "a collective effort by neighbors or community members to erect the frame of a barn for one of them, accompanied by a social gathering" is attested by 1849.

Middle English sēchen "go in search or quest of; strive for, try to attain," from Old English secan, seocan "search for; pursue, chase; long for, wish for, desire; look for, expect from," influenced by Old Norse soekja, both from Proto-Germanic *sokjanan (source also of Old Saxon sokian, Old Frisian seka, Middle Dutch soekan, Old High German suohhan, German suchen, Gothic sokjan).

This is reconstructed to be from PIE *sag-yo-, from root *sag- "to track down, seek out" (source also of Latin sagire "to perceive quickly or keenly," sagus "presaging, predicting," Old Irish saigim "seek"). The natural modern form of the Anglo-Saxon word, had it not been influenced by Norse, is in beseech. Related: Sought; seeking. 

By late Old English as "ask a question." Seek-sorrow (1580s) was an old term for "a self-tormentor, one who contrives to vex himself." Seek-no-further (or farther) as the name of a type of eating apple is by 1660s.