Assuming a block size of 13,200, 6,000 volumes at the site, and an average of 2 files per volume, the following is the calculation:

1. x1 is the 13,200 / 660 = 20 entries per block
2. x2 is the 6,000 volumes at the site
3. x3 is the 2 files per volume
4. num_rcds = [(6,000 * 2) + 6,000] * 1.1 = 19,800

num_blks = (19,800 / 20) + 1 = 990