RedHat Enterprise Linux 6 Beta 1 has finally been released as a public beta. It is available as an ISO from the public RedHat FTP site.
A couple of days ago, I decided to play with the beta, and I discovered, as expected, there are a lot of significant differences between RHEL5 and RHEL6.
The the main difference which I found to be very frustrating is that there is no longer any support for Xen dom0.
I had heard about RedHat’s decision to stop supporting Xen, but I did not think that this would mean they would stop shipping it with the distribution.
The loss of dom0 support means that you can no longer use RHEL as a Xen virtualization host, rather only as a guest under other Xen supporting distributions.
Xen has been dropped in favour of Kernel-based Virtual Machine (KVM), which is a virtualization infrastructure included with the Linux kernel. Linux KVM is a hardware-assisted virtualization infrastructure which requires the CPU to have a special CPU feature called Intel-VT on Intel CPUs and AMD-V on AMD CPUs.
KVM has limited paravirtulization support, but I found in my very simple tests that fully paravirtualizaed guests inside Xen had much better performance.
This latest release of RHEL also means that my RHCE will soon expire. I am hoping to get re-certified as soon as I can. At the same time, I am also considering taking the “Red Hat Certified Virtualization Administrator” course and exam, but I still have some time to think over that. 🙂