The preceding sections dealt with the concept of volumes in BS2000. The following table provides an overview of the characteristics of the various types of volumes..
Volume characteristics | Public volumes (pubsets) | Private volumes | ||
|---|---|---|---|---|
Disk | Net-Storage 1) | Disk | Tape | |
Number of jobs which may use the volume concurrently | Any number | Any number | Any number(exception: exclusive reservation) | No more than 1 |
File protection | Full file protection by DMS | Full file protection by DMS in BS20002) | Full file protection by DMS | Full file protection by DMS |
Permissible processing method | DMS access methods; I/O macros for system files (RDATA etc.) | DMS access methods; I/O macros for system files (RDATA etc.) | DMS access methods; I/O macros for system files (RDATA etc.) | tape access methods of DMS: SAM, UPAM and BTAM |
Labels | Standard labels | Standard and nonstandard labels | ||
Volume serial number (VSN) | 6 alphanumeric characters; see "Public volumes (pubsets)" | Standard name derived from the pubset (6 characters, alphanumeric); userdefined name like private disk | 6 characters, alphanumeric; does not begin with "PUB" and does not contain a period | 6 characters, alphanumeric; does not begin with "PUB" and does not contain a period |
Volume request | Pubsets do not need to be requested by the user | Net-Storage volume does not need to be requested | Disks must be requested by the user | Tapes must be requested by the user |
Dynamic storage space management | Yes | Yes | Yes | No |
Volume reservation | Not possible | Not possible | Mandatory, otherwise the job may be aborted if the volume is not available | |
| 1) | Net-Storage expands the storage space on public volumes, but is itself not counted as a public volume |
| 2) | The BS2000 protection attributes cannot be implemented on open systems which have access to Net-Storage files. By default, node files are assigned to the relevant user by means of user and group numbers (UID, GID), and read and write authorization is only entered for this user. However, the UNIX rights can be modified from the UNIX side (for details, see section "General conditions") |