Recalling Data in a Distributed Processing System
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
A multihost system includes programming controls that migrate aged data from the primary external data storage DASD (direct-access storage device) to magnetic recording tape for long-term storage. When any of the hosts need data that has been migrated to tape, a recall operation is instituted. Each host institutes its own recall operation independent of the other hosts. When a first host has a mounted tape volume for recall or other purposes and another host decides it needs a data set which is recorded on that mounted tape volume, the other host examines a common data set in DASD to see if the desired tape volume is mounted in the multihost environment. If it is mounted, the other host sends a request to the host mounting the tape to transfer the data set desired to be recalled to a shared DASD.