Irrespective of the source and target HSIs, there are some general aspects which should be borne in mind when migrating a server:
Number of BS2000 CPUs of a server
When the multiprocessor level of a server changes when migration takes place, this can also result in a change to the performance behavior of the software running on the server. In such a case check the relevant parameters and settings which control the performance behavior of the software.
In particular check the settings for OLTP mode, e.g. the number of UTM tasks used, the number of TAC classes, the number of tasks per TAC class, the number of DBHs, and the buffer sizes of the database system.
Adjust the parameters if necessary.
Detailed information on this is provided in the manuals on openUTM, in the "SESAM/SQL Server Performance" manual [27 (Related publications)], and in the ORACLE manuals.
Main memory size
When migration takes place, check whether the main memory needs to be increased to enhance the performance:
to avoid unnecessary paging I/Os
to expand the buffer for OLTP mode
to expand the caches for the software product DAB
Operating mode: Native or under VM2000
Take note of the following points if, in the course of migration, native mode is to be switched to virtual mode under VM2000:
Virtual mode causes an overhead which must be allowed for accordingly when calculating the performance of the new server. The amount of overhead depends on the configuration, see "Virtual machines".
Take note of a few constraints when configuring VM2000 to avoid unnecessary overhead. See section "Recommendations for an optimal configuration".