The total size of an A/UX file system (both UFS and SVFS) is measured in
blocks. The number of blocks is stored in each file system's super block
with the declaration of "long fs_size". This value can be stored up to
2**32 blocks. The block size of the file system in UFS, for instance, can
be 512 bytes, 1K, 2K, 4K, or 8K. In SVFS, the default file system block
size is 1K.
From the number of blocks and the file system block size, the maximum size
of an A/UX file system ranges from 2**32 Kbytes to 8*2**32 KB.