Victor, You should be able to reply on the blocksize recorded in rmm. Just like other tape systems it gets it from the system. Assuming you are on a supported level of z/OS, rmm should record all you need to know about logical and physical view of the data sent to tape by the application and actually on tape. You dont say what the actual tape drive is - somewhere you should 3490 I think. I suspect you are using virtual tape - is that correct? If so, how compression is handled depends on the tape 'hardware' you are using ..... an appliance like IBMs TS77xx, or software like VTAPE .....
Compression done in s/w will really hurt you. The hardware compression should barely be seen by the host system measurements. Modern tape drives (non-virtual) dont care about your/application choice of blocksize and will write larger blocks to the tape media - Russell already told you that ...... If you need help - we all want to offer it, but if you dont give enough details you will never get a correct answer - just guesses. Mike ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
