As Mike told, in real 3490E, block count in block ID (32-bits) is 22-bits long. High order 10-bits in 3490E block ID is used other purpose. In case of 3590 as well as 3592, the block count is 32-bits long.
But in 3490E emulation mode of 3590/3592, you can use 32-bits block count. I think that STK T1000, Bus-Tech MDL, as well as TS7700 provide 32-bits block count to utilize large capacity media. I coud not find APAR OW49829 which supports 32-bits block count. Please look at 3590/3592 Introduction and Planning Guide and old Redbook IBM 3590 Multiplatform Implementation SG24-2594. In addition to this, please look at DCBE macro description in DFSMS Macro Instructions for Data Sets. DECB macro has a parameter CAPACITYMODE=XCAP. Minoru Massaki 2011/6/21 Mike Wood <mikeww...@hotmail.com>: > Radoslaw, I believe the 'limit' that most likely causes problems is the > block ID. > 3490/3590 devices use different formats. If you look at the doc for the NOTE > and POINT macros for sequential data sets in DFSMS pubs you will get some > idea of the differences. > Basically, the 3490 blkid limited the number of blocks written to the tape. > When small blocks are used you might not be able to use the entire tape > media. The blkid for 3590 supports many more blocks. > > Depending on how the data is accessed, having more blocks on an emulated > tape than can be addressed by blkid, may not be a problem. Or, perhaps the > emulation uses newer blkid format, and as long as mvs does not manipulate > them, they likely work ok. > > As for tape capacity, the system has always made assumptions about this > based on the media and recording format detected and used. However, with > virtual devices, there was recent support added ( library and dfsms) to > allow the library to pass the volume capacity to the system. You can see a > field in the IFGTEP control blocks where the capacity can be passed from > OPEN to the tape management system - this works for all real '3590' and > recent IBM virtual library levels. > > Mike Wood > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO > Search the archives at http://bama.ua.edu/archives/ibm-main.html > -- 全先 実 - Minoru Massaki (M*M) E-mail: mmass...@gmail.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
