Patent ID: 7949799

Claim:
A storage apparatus comprising: a basic storage device including a control unit configured to control external access; and an add-on storage device configured to be connected to the basic storage device, the add-on storage device comprising: a first request receiving unit configured to receive a first operation stop request output from the basic storage device to the add-on storage device, a second request receiving unit configured to receive a second operation stop request different from the first operation stop request received by the first request receiving unit, a communication monitoring unit monitoring communication from the basic storage device, and an operation stop processing unit performing processing for stopping the operation of the add-on storage device when the first request receiving unit receives the first operation stop request, wherein the operation stop processing unit determines the validity of the second operation stop request received by the second request receiving unit based on a monitoring result obtained by the communication monitoring unit, and stops the operation of the add-on storage device when the second request receiving unit determines to the received second operation stop request is valid.