Monika, Further to Mike's suggestions and advice, if you need to know the exact size, the number and size of "short blocks" is an unknown factor. DS1LSTAR points to the end of the (last) extend and from the number of tracks you can calculate the number of blocks but the blocks may not be full !
RECFM=U|VB|FB frequent append (DISP=MOD) or CLOSE TYPE=T or just explicit BSAM WRITE may write (over time) many *short* blocks (smaller than BLKSIZE). Andreas F. Geissbuehler AFG Consultants Inc. http://www.afgc-inc.com/
