If you’re running (or plan to run) Red Hat Enterprise Linux (RHEL) for LinuxONE or for IBM Z, Red Hat offers compelling reasons to upgrade at least some of your Linux guests to RHEL 7.5, announced and available this week. Here are some highlights.
Red Hat now supports RHEL running under the KVM hypervisor for LinuxONE and Z, and of course you can still run RHEL under z/VM and “natively” within LPARs. To operate in a Red Hat supported way you must run your RHEL 7.5 KVM guests using the kernel-alt packages, a.k.a. “Structure A,” which updates the kernel to 4.14. Stefan Raspl explains a bit more here.
Also, with the 7.5 “Structure A” release, RHEL supports the new Guarded Storage Facility (GSF) instructions in the IBM z14 (including ZR1 model), LinuxONE Emperor II, and LinuxONE Rockhopper II machines. This support within the Linux operating system is a prerequisite for Pause-less Garbage Collection in Java Virtual Machines (JVMs) for Linux, presumably coming soon in a 64-bit JVM releases for Linux on LinuxONE/Z. Pause-less GC apparently won’t be relevant to 31-bit JVMs because their heap sizes cannot be “too large” for these purposes.
RHEL 7.5 Structure A also provides the ingredients required for pervasive encryption with protected keys.
There’s more, of course. You can check out the full 7.5 release notes for details.