Red Hat Enterprise Linux (RHEL) version 6.3 became generally available today, ushering in a new era of virtualization scalability. The RHEL 6.3 update is the third major update to Red Hat's flagship platform since RHEL 6 was initially introduced in 2010.
"We've increased the number of CPUs that a virtual guest can support, from the previous limit of 64 up to a new limit of 160," Tim Burke, Vice-President of Linux Engineering at Red Hat, told InternetNews. "Scalability is important because we're seeing more high-end compute-intensive workloads that are being run on virtualized guests."
On the topic of beefy virtual guests, Red Hat has also grown the amount of memory that can be allocated to virtual guests. In RHEL 6.3, memory per virtual guest has moved from 512 GB in previous releases up to 2 TB. Virtual disks have also been scaled up in the SCSI subsystem from 25 disks per guest up to thousands per guest.
From an availability perspective, Red Hat is introducing Dynamic CPU Hotplug, technology that allows a virtual guest to add more virtual CPUs while it is still running.
"Previously, you had to momentarily shut down the virtual guest in order to gor it, so this is really a run-time enhancement," Burke said. "Similarly, at run time you can now dynamically scale the size of the disk volumes for a virtual guest."
Some of the scaling improvements that Red Hat users may see come from new Intel Xeon E5 CPUs, although Burke stressed that most of the scaling improvement comes from Red Hat coding changes.
"It's fundamentally the KVM architecture. KVM is a thin layer on top of the bare metal hardware, so we don't have to do everything twice," Burke said.
Even with the current high levels of scalability, Burke insisted that there is still room for even more scale in the future. He noted that when it comes to Big Data and Hadoop, for example, those workloads tend to be highly parallelized and utilize a large number of CPUs.
"Ultimately, our objective is to provide a seamless experience for customers moving from bare metal to virtual, and to cloud," Burke said. "Virtualization used to be just about workload consolidation, and it's still a primary driver, so this isn't an academic exercise and we are seeing hands-on deployment."
As part of the effort of further supporting the move to virtual infrastructure, RHEL 6.3 includes the new Virt P2V tool.
"You can take a RHEL system or a Window system and run this tool on it, and it creates an image for a virtualized guest," Burke said.
Security also gets a major boost in RHEL 6.3 with advanced two-factor authentication for OpenSSH. OpenSSH is one of the primary methods by which Linux server admins remotely access their boxes.
"Two-factor authentication has been around forever; it just wasn't previously integrated with OpenSSH," Burke said.