Let me tell something about the background. Long time ago we decided to set DS1LSTAR to zero, because it is to small for larger partitions. The TTR field allowes us partition sizes of max 3GB for a usual Linux ECKD geometry (12 blocks per track and 4k block size). We did not want this restriction.
The alternative, using the extended format (DS1LSTAR and DS1TRBAL), did also not work. Sure, then we had a TTTTR field to flag the partitions as used, which is large enough. But to use DS1TRBAL, the data on the ECKD DASD have to be in a certain format, e.g. a 32 byte prefix for each block and others. And in addition, z/OS would expect other than Linux data behind this format and we have again a problem. The compromise was to set DS1LSTAR to zero, to indicate here is something different and to document this. regards, Volker
