All DFSMShsm hosts must use the same serialization method. If not, at least one of the hosts will shut down (that is, each host detecting a mismatch will shut down).

If an HSMplex has both Version 1 Release 5 and pre-Version 1 Release 5 running concurrently, then the Version 1 Release 5 hosts cannot specify RNAMEDSN=YES. If RNAMEDSN=YES is specified, hosts that detect the mismatched serialization method will shut down.

Each HSMplex using an old serialization method will interfere with other HSMplexes. HSMplexes using the new serialization method will not interfere with other HSMplexes. However, in a two-HSMplex environment, one can use the old method and the other can use the new method; neither one will interfere with the other.