The formatting properties of an SF pubset or volume set are defined during initialization and are therefore unchangeable over the complete lifetime of the SF pubset or volume set. All volumes (disks) of an SF pubset/volume set have the same formatting property. Systems support defines it during volume initialization (with SIR or VOLIN):
file processing with and without PAM key usage in processing mode: K and NK
minimum allocation unit (min. AU) with which DMS assigns space for files on the volumes of the pubset: 6 KB, 8 KB or 64 KB
minimum I/O transport unit (min. TU) in which volume inputs and outputs are to be made: 2 KB or 4 KB
Corresponding pubset formats are available for the listed volume formats and these can be retrieved with the SHOW-PUBSET-CONFIGURATION command.
The following volume format combinations are generally possible:
Volume format | Processing | min. AU | min. TU | Max. number of volumes per |
K format | K | 6 | 2 | 32 |
NK2 format | NK | 6 | 2 | 32 |
NK2 format | NK | 8 | 2 | 255 |
NK4 format | NK | 8 | 4 | 255 |
NK2 format | NK | 64 | 2 | 255 |
NK4 format | NK | 64 | 4 | 255 |