Red Hat Enterprise Linux 6.5 Brings the Goods, Softly but Surely
"Softly, softly, catchee monkey" is a very odd phrase that is said to originate from the Ashanti people in Ghana. Essentially it means that the best way to achieve an objective is through quiet application.
While it may not sound like a very exciting approach to life, "softly, softly, catchee monkey" just about perfectly sums up Red Hat's approach to virtualization technology. It doesn't grab the headlines the way that VMware likes to with its software-controlled this and cloud-connected that, yet slowly but surely Red Hat is improving its sever virtualization offering. You may not notice it, but year by year there is no doubt that it is getting progressively stronger.
The latest improvements have just landed with the general release of Red Hat Enterprise Linux (RHEL) 6.5, after a short period in beta.
What's New in RHEL 6.5
So what exactly are the new virtualization technology goodies that RHEL 6.5 brings?
Before diving into the improvements in KVM, Red Hat's server virtualization hypervisor, it's worth mentioning that RHEL now comes with improved drivers for Microsoft's Hyper-V hypervisor and VMware's server virtualization ecosystem. What this means is that RHEL 6.5 works better as a guest on these two server virtualization systems than it did before: there's a better signaling protocol between the host and the guest for Hyper-V, and the VMware network para-virtualized driver has been updated to the latest upstream version.
Now, on to the KVM improvements. "Virtualization updates in Red Hat Enterprise Linux 6.5 include a number of bug fixes in areas such as live migration, error reporting, hardware and software compatibility. In addition, performance and general stability improvements have been implemented." That's how Red Hat puts it, at least.
But as far as specifics go, there's:
- Improved read-only support for VMware's VMDK image file format, including its sub-formats.
- Read-only support for Hyper-V virtual hard disk, or VHDX, image formats, as created by Microsoft's Hyper-V.
- Full support for the Windows guest agent, delivered with its own installer in the supplementary channel together with virtio-win drivers.
- CPU hot plugging and hot unplugging for Linux guests; CPUs can be enabled or disabled while the guest is running, thus mimicking the hot plug or hot unplug feature.
- Conversion of VMware Open Virtualization Format (OVF) and Citrix Xen guest conversion to KVM thanks to an upgrade to the virt-v2v conversion tool.
- Increased KVM virtual memory scalability in a single guest right up to a whopping 4TB.
- A "technology preview" of a feature that allows a guest panic to cause a new pvpanic virtual device that can be wired into the virtualization stack to send a notification event to management applications.
Support for Docker Containers
RHEL 6.5 also provides limited support for Docker containers. These are virtualized applications that run on — and can be moved between — VMs, bare metal, OpenStack clusters or public clouds. (To use them it's necessary to get additional software from Docker to provide Linux Container functionality which isn't fully supported in RHEL 6.5 at this time.)
Look, there's nothing here that is going to set the world on fire in the way that VMware periodically does as it unveils its latest acquisition or the newest version of its strategy for global data center domination.
It's just that slowly but surely, Red Hat is evolving a powerful server virtualization offering. Softly, softly, catchee monkey, in other words…
Paul Rubens is a technology journalist and contributor to ServerWatch, EnterpriseNetworkingPlanet and EnterpriseMobileToday. He has also covered technology for international newspapers and magazines including The Economist and The Financial Times since 1991.
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