The relationships between unit names that conform with BS2000 language conventions and those that conform with the language conventions of the storage systems are illustrated in the figure below.
Figure 3: Assignment of the of units (BS2000 and storage system language conventions)
The files (:A:$<user>.<file1..6>) reside on pubset A. Pubset A consists of the units 5000..5003 together with the allocated volumes PUBA00..PUBA03. These are assigned to the logical volumes #0000..#0003 in the storage system. The logical volumes are configured in pools (thin pools or RAID groups of physical volumes). The configuration depends on the RAID level and on the storage system (in figure 3 a thin pool is illustrated as an example).
In order to address and use the logical volumes of a storage system in BS2000, they are generated on /390 servers when the hardware is generated with IOGEN or by means of a dynamic I/O configuration change, see section "Settings for /390 servers". No generation is required in BS2000 for x86 servers.
When local replication is used, the units must also be generated in BS2000.
At least the source units must be generated when using remote replication in BS2000. The target units must be generated, for example, on the server, that is to use them in the event of a disaster.