Read Home Address in Cached Peripheral System
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
A cached DASD (direct-access storage device) has a directory attached o to a cache identifying data in the cache from the DASD which is readily acceptable to a host or identifies space in the cache for receiving data from a host for later transmittal to the DASD. A common channel command is to read the home address (HA) of a DASD track. In the event of a cache miss, the DASD is accessed and the HA is sent directly to the host. For a cache hit, the directory is accessed with the data identifying fields in the directory being reassembled for sending the true HA to the host.