A single-feature pubset (SF pubset) consists of one or more homogeneous volumes which must have identical properties (disk format, allocation unit). The disk assigned number 0 is known as the Pubres. The Pubres is the obligatory system disk of an SF pubset. It contains, among other things, a directory of the disks belonging to the pubset and a reference to the start of the TSOSCAT file catalog.
In the example below the SF pubset with catalog ID ABC consists of three volumes with the VSNs (in point notation) ABC.00, ABC.01 and ABC.02.
Volume configuration of an SF pubset (example)
If a file named “MY.LIST” exists under user ID “ALLKIND” on one of the volumes in SF pubset ABC, the path name is: “:ABC:$ALLKIND.MY.LIST”
Properties of SF pubsets
An SF pubset represents the provision of a limited, homogeneous service. If the service requirements of a file change the user must move the file to another pubset.
SF pubsets can be enlarged by adding empty volumes. The volume properties must match those of the pubset (see "Setting up and replacing SM pubsets").
The size of an SF pubset can be can be reduced by removing empty volumes. The system provides the option of setting allocation restrictions as an aid for clearing volumes.
If a single volume in an SF pubset fails, the complete pubset is taken as failed.
SF pubsets are suitable for use as home or paging pubsets.