I was looking at an old mainframe log file I kept. I was looking up various words. Since I’ve been working with VM lately for some reason I decided to look for DMKRIO. I was shocked not to find it in my log file. How can this be? I remember DMKRIO. I did find a HCPRIO…which I don’t remember. Apparently I added some device to it. Long story short I found a Conversion Guide and Notebook PDF for VM/ESA. There was a section that said…Converting DMKSYS and DMKRIO [S370]. You cannot use DMKSYS and DMKRIO files in the new system. IBM strongly recommends that you convert your DMKSYS and DMKRIO files to a CP system configuration file. The CP system configuration file, named SYSTEM CONFIG, is new. The other method of defining your CP configuration is with HCPSYS and HCPRIO files. It is possible to convert your DMKSYS and DMKRIO files to HCPSYS and HCPRIO files but this makes your conversion more difficult.

I found a reference to SYSTEM CONFIG later in my log file so evidently the DMKSYS and DMKRIO were eventually converted to IBM’s recommendation.

So my previous job I think I was probably using VM/SP, and there DMKRIO. I don’t have a log file (at least not handy), for that job (it might be on a VMFPLC2 tape).