Patent ID: 6341329
Filing Date: 2002-01-22
Classification: G06F

Abstract:
A method for emulating a first data storage device with first characteristics and responsive to individual first requests in a first set of input-output requests with a second data storage device with second characteristics and responsive to individual second requests in a second set of input-output requests wherein a host with a main storage memory and at least one central processor includes means for issuing the first and second requests, said method comprising the steps of:A) intercepting in the host each first request from the host, B) for each first request that identifies a first storage device being emulated by the second storage device: i) building in the host at least one second request according to the characteristics of the second data storage device, ii) transferring the at least one second request to the second data storage device from the host iii) signalling to the host the completion of each operation initiated by each of the at least one second requests, and, iv) signalling to the host, upon the completion of all of the at least one second requests associated with the first request, the completion of the corresponding operation in response to the first request whereby the operation of the second data storage device emulates the operation of the first data storage device and acts as a virtual first data storage device, and C) for each first request for other first storage devices transferring the first request and signalling to the host the completion of the operation initiated in response to the first request.