Assuming that the block size is 6,378 and the number of data sets that are processed by Control‑M/Tape is 1,500, the following is the calculation:

1. x1 (sd_num_rcds) is 15,000
2. x2 is 15,000 * (57 + 6) = 945,000
3. x3 is (945,000 / 6378) * 2 = 296

sdi_num_blks = 296 * 1.05 = 311