Ahead of its Red Hat Summit in Boston next week and the reporting of its financial results for fiscal Q1 yesterday, commercial Linux distributor Red Hat is pushing out its next iteration of the Enterprise Linux operating system for servers and workstations.
RHEL 6.0 launched in November 2010, and it was a major update, with more than 2,058 programs (twice as many as in RHEL 5) and a move to the Linux 2.6.32 kernel. With the RHEL 6.3 release available today, a big focus is the usual updating in the kernel and in the driver stack to take advantage of new hardware that has come to market in the past six months.
"Hardware enablement is a big piece of every release," Tim Burke, vice president of Linux engineering, tells El Reg. In this case, there are a number of optimizations that have been made explicitly for Intel's new Xeon E5-2400, E5-2600, and E5-4600 processors, which came out in March and April, as well as Advanced Micro Devices' Opteron 6200s, which launched last November.
There's a "full spectrum" of device driver updates, and tweaks to the KVM hypervisor being championed by Red Hat against VMware's ESXi, Citrix Systems' XenServer, and Microsoft's Hyper-V that improve memory handling and I/O breakpoint handling for virtualized guests. The update also includes tweaks to the Linux kernel to support forthcoming iron – new Power7+ and "zNext" processors are expected from IBM later this year and Intel and AMD are also working on new CPUs – but Burke cannot confirm or deny that these chips are already supported in the RHEL 6.3 release. "Some of the best stuff in our release, we can't even tout at the time because of NDAs," says Burke with a laugh.
But we all know that support for these future chips is in the kernel because we know they need to be tested before coming to market.
Life is somewhat easier for Red Hat now that it has dropped support for the Xen hypervisor with the RHEL 6.X family as well as killing off support for Itanium processors from Intel. While Red Hat supports the running of RHEL inside of IBM's PowerVM hypervisor on Power-based systems as well as on z/VM and LPARs on IBM mainframes, those hypervisors are under the control of Big Blue and are not Shadowman's problem. The situation could get more interesting once ARM chips get a proper KVM hypervisor, but as Burke points out, the ARM architecture does not have the on-chip support for virtualization that x86, Power, and mainframe processors have (as does Itanium and Sparc T series chips, which cannot run RHEL 6). Until ARM chips do get this, KVM has to run in paravirtualized mode and the "performance would not be that great."