Slide 22 of 33
Notes:
Even in HP-UX 10.xx one can specify HFS file system geometry with the mkfs program.
Ns multiplied by nt determines the so-called cylinder size. This is the amount of data that can be addressed by the disk drive as the platters rotate before requiring the read/write heads to move to a new location on the disk.
Cg is used by the file system to determine how it fragments large files. HFS specifically tries to limit how contiguous the data in any given file can be. While this tends to slow down I/O to large files, as the disk drive fills I/O tends to degrade less than it might otherwise.
