Step 1: Plan how the new subdomains representing each subplex will fit into your DNS hierarchy

Decide whether the new subdomain names should exist at the same level as the existing subdomain representing the sysplex that is being divided into subplexes, whether the new subdomains should become child domains of the existing sysplex domain, or whether there will be a mixture of the two.

For example, if the existing subdomain for the sysplex is mvsplex.mycorp.com, the new subdomains that represent the subplexes can be at the same level in the DNS hierarchy, such as mvsplex1.mycorp.com and mvsplex2.mycorp.com. Alternatively, you can create the new subdomains as child domains of the existing sysplex domain, such as subplex1.mvsplex.mycorp.com and subplex2.mvsplex.mycorp.com.

For the following examples, assume that the sysplex and ADNR are configured as shown in Table 1.

To convert this sysplex to a subplexing environment, one of the subplexes can use the existing domain name as the existing sysplex, and the other subplexes become subdomains of that domain, as shown in Table 2.

Another possibility is to assign each subplex as a child domain of the original sysplex domain, as shown in Table 3. In this case, the existing sysplex domain no longer contains any resource records that represent hosts or server applications, but instead is merely the parent of the new subplex subdomains.

Another alternative is to create new domain names for each of the subplexes at the same level of the DNS hierarchy as the existing sysplex domain, and retire the existing sysplex domain name, as shown in Table 4.