For the purpose of upgrading MIM to a new release, it is often necessary to temporarily run mixed releases of MIM in the same MIMplex. This can be accomplished with MIM versions 11.7, 11.8, 11.9, 12.0, 12.1 and 12.5 by using the MIMINIT COMPATLEVEL initialization setting.
Component:MIM-Resource Sharing-for z/OS
The way that different releases of MIM co-exist in the same MIMplex is by using a common COMPATLEVEL value. Historically, a release of MIM has only been backward compatible with previous releases of MIM. MIM 11.7 and 11.8 are now exceptions to that rule. Forward compatibility is provided by means of a PTF each for MIM 11.7 and 11.8, allowing each release to run with a COMPATLEVEL value that is higher than itself.
MIM 11.7 PTF RO37535 adds support for the values of 11.8 and 11.81 on the MIMINIT COMPATLEVEL statement and the ACTIVATE COMPATLEVEL command. RO37535 is available for download at CA Support Online (CSO).
MIM 11.8 PTF RO38458 adds support for the value of 11.81 on the MIMINIT COMPATLEVEL statement and the ACTIVATE COMPATLEVEL command. RO38458 is also available for download at CSO.
With the appropriate PTF applied, MIM 11.7 and 11.8 can be forward compatible with a pseudo (internal) release called 11.81. The 11.81 value was necessitated during the MIM 11.9 Development phase in order to allow MIM 11.7 and 11.8 to be forward compatible with MIM releases 11.9, 12.0, 12.1 and 12.5. MIM 11.9,12.0, 12.1 and 12.5 at the base levels supports values of '11.81' and '11.9' for COMPATLEVEL. The common value for the 4 releases is 11.81, which means it is possible to have a MIMplex that consists of some mix of 11.7, 11.8,11.9, 12.0, 12.1 and 12.5 systems.
The MIM Installation Guide has a section called COMPATLEVEL Considerations that has detail COMPATLEVEL information for introducing a new MIM release into a MIMplex. This section includes examples and information for any customer who also runs MIM VM 11.5. MIM manuals for the supported releases are available at CSO in HTML format for viewing online and in PDF format for downloading.
A section called: "Migration Information - Compatlevel Considerations" in the MIM Release Notes also provides information on the use of COMPATLEVEL.