These systems of a MAREN network can be split into groups, which are called domains. A domain can be assigned any number of systems. A domain consists not only of the systems, but also of the tapes which are processed on these systems.
Domains represent a protection mechanism: access to tapes is only possible within the domain involved. This applies on the one hand for accesses to data stored on the tapes. On the other hand it also applies for accesses to the MAREN catalog, in other words to the attributes of the tapes.
The use of domains is optional. The conditions and requirements in the data center determine whether it makes sense to structure the MAREN network with domains.
User roles
When domains are used, three roles with different authorizations exist:
The MAREN user. The statements of the MAREN user program are available to the MAREN users. Users work solely in their own domain. For the users it makes no difference whether they are working in a domain with one or a specific number of systems or in a MAREN network with the same systems.
The Domain Administrator (DA). DAs are permitted to execute statements of the MARENADM administrator program within their own domain. They may not work in other domains.
The All-Domain Administrator (ADA). ADAs administer the domains using special statements of the MARENADM administrator program. Furthermore they are permitted to perform DA tasks in all domains. To do this they can explicitly adopt the role of the DA. The default domain and system-specific defaults then apply for the ADA. The ADA must have authorization to execute MARENADM statements on at least one system in the MAREN network.
The roles of ADA and DA are protected by passwords, see the MARENADM statements MODIFY-GLOBAL-PARAMETERS and MODIFY-MAREN-PARAMETERS.
In the MAREN manuals the term “MAREN administrator” is used to mean the following:
Generic term for all users with administrator rights regardless of whether or not domains are used.
Administrator in the MAREN network without domains.
The meaning is made clear by the context. When this is not the case the particular administrator roles are named explicitly: ADA, DA, administrator without domains.
Assignment of tapes to domains
A domain consists not only of the systems, but also of the tapes which are processed on these systems. The MAREN catalog contains this assignment of tapes to domains.
When a tape is reserved by a system and is, if required, being written to, it belongs to this system’s domain. The tape can then not be processed on the systems of the other domains. Nor is information about this tape visible in the MAREN catalog on the systems in the other domains.
In addition to the domains which are defined as a group of systems, there is also another domain, known as the standard domain (STD-DOM). Generally no systems belong to this domain, but the tapes which can be processed on all systems. These comprise:
Free tapes which are available for all systems to reserve. (Free tapes can, however, also be assigned to a domain.)
Reserved tapes which can be accessed by all systems.
Tapes which were reserved in an earlier MAREN version and have not (yet) been assigned to a domain.
The following figures illustrate two typical applications of domains. They differ in the assignment of the reserved and free tapes to the standard domain and the other domains. For information please refer to the FREE-VOLUMES operand of the MODIFY-DOMAIN-PARAMETERS MARENADM statement.
Example 1: Free tapes in the standard domain, reserved tapes in the other domains
Example 2: Reserved and free tapes in all domains
Statements
Domains are set up and administered using MARENADM statements. Some statements are intended exclusively for use with domains. In other statements operands are available which are only meaningful when domains are used. These statements and operands largely concern all domains or one domain as a whole and are available to the All-Domain Administrator.