A method and a system for maintaining consistency of replicated files distributed over a plurality of independent processing slave nodes part of an application tier of a multi-tier clientserver data processing system are described. An empty copy of the virtualized application package is generated from a skeleton file. When the power supply is rotated inwardly, a retention member of the power supply presses the tilted portion toward the sidewall, so that the blocking portion blocks the sliding member of the storage device in a corresponding slideway of the bracket.