Gentlemen, Our experience is from VSE/ESA 2.3 + VM/ESA 3.1 to z/VM 5.2 and then to 5 .3. We run in a 9672, z890 and now in a z9.
It is easy to upgrade VM releases, but we spent three years migrating fro m ACF/2 to Top Secret as directed ( forced ) by CA. This was the real probl em but I discarded the idea to work in a second level VM the third level VSE . At the same time we migrated from ACF/2 to Top Secret in the VSE/ESA and were ready to go for z/VSE. We have half of the VSE´s in z/VSE 3.1 and stopped because the CPU incr ease from VSE 2.3 to zVSE 3.1 was between 15 and 20 percent. And no CICS was migrated to Transaction Server. The issue is that VSE/ESA, VM/ESA and ACF/2 have no support but there are some costs to pay, working and CPU overhead. Regards. Marcelo.
