When running applications with certain input/output requirements, it makes sense to group similar public volumes together in pubsets.
One pubset should comprise 4 or less public volumes. The advantage of this is that, in the event of a failure, only the pubset concerned is blocked, and operation can continue to a limited degree with the remaining pubsets. Creation of a standby pubset (a copy of the home pubset) for the purpose of a quick restart is recommended (for a description of handling see the “Introduction to System Administration” [10 (Related publications)]).
Using a number of SF pubsets improves performance by increasing the range of distribution options for files.
Notes on the distribution of the TSOSCAT system files, paging areas and SYSEAM are given in section “Creating system files”.
In order to distribute the input/output requirements of users who work under different user IDs by means of system specifications, the following parameters must be taken into account when /ADD-USER or /MODIFY-USER-ATTRIBUTES is used:
/ADD-USER USER-IDENTIFICATION=xx, DEFAULT-PUBSET = *HOME / <catid> 1.
PUBSET = *HOME / <catid> 2.
PUBLIC-SPACE-LIMIT = <max>/<integer> 3.
<catid> identifies the pubset in which the user can access files without the specification of a catalog ID, e.g. in /CREATE-FILE, /ADD-FILE-LINK, /MODIFY-FILE-ATTRIBUTES.
<catid> defines the pubset which can be accessed by the user. It is only possible for a user to access a particular pubset if an entry exists for him/her in the user catalog of the relevant pubset.
<max> specifies the maximum public space available to this user ID for the pubset specified in 2.
One exception is when the pubspace value for a pubset is specified as zero for a given user ID. This user then has access to all the files whose access rights are set appropriately. He/she cannot, however, create any files in this pubset.