Red Hat pitches x64 virtualization with KVM rollout
RHEVing up server hypervisors
Commercial Linux distributor Red Hat today got its freestanding, bare-metal Enterprise Virtualization hypervisor, a hardened version of the KVM hypervisor it took control of last summer, to market. That makes Red Hat a player as x64 servers the world over are set for a massive wave of virtualization.
Red Hat announced its intentions to go up against VMware, Citrix Systems, Microsoft, and Oracle in the race to deliver commercial-grade server virtualization for x64 iron back back in February, five months after shelling out $107m to buy Qumranet, the company behind the open source KVM project and one that was creating a stack for serving up virtual PCs. In mid-June, the standalone Red Hat Enterprise Virtualization, or RHEV, hypervisor went into beta and in early September, an embedded version of the RHEV hypervisor was buried in the guts of the Red Hat Enterprise Linux 5.4 release.
With the launch of RHEV H, the nickname of the hypervisor, and its companion, RHEV Manager (dubbed RHEV M because everyone in IT talks in shorthand), Red Hat has almost completed the rollout of the virtualization products it outlined in February. The RHEV Desktop edition, which will be a bare-metal hypervisor for PCs, is in beta now and will be generally available in early 2010, according to Navin Thadani, senior director of the virtualization business at Red Hat.
This packaging is a little different from what Red Hat was talking about back in February. Red Hat said it would be embedding KVM in a future RHEL 5 release and then putting out a standalone hypervisor based on KVM (and using RHEL as the kernel to support the hypervisor); beside this would be RHEV Manager for Servers, a hypervisor and virtual machine management tool aimed at server customers, and RHEV Manager for Desktops, a commercialized version of the SolidICE virtual desktop infrastructure (VDI) setup that Qumranet originally went to market with shortly before Red Hat ate the company. With today's announcement, the RHEV hypervisor and related RHEV Manager tool may be separate products, but they are bundled as one and have a single support price: $499 per managed server socket per year for a standard support contract (five days, business hours) and $749 per managed server socket per year for premium support (24x7).
Thadani says that Red Hat may offer a standalone packaging of the RHEV Hypervisor that does not include the RHEV Manager, but didn't seem thrilled with the idea on a call announcing the product. Most likely because if customers could get the hypervisor and support it themselves for less money, they probably would do just that.
But a lot of the functionality enabled in the hypervisor - such as live migration, VM restarts, load balancing, power management, thin provisioning, and snapshotting for both Linux and Windows instances running atop RHEV - is only accessible through RHEV Manager. But hey, RHEV M has a search-driven interface that makes it easier to use than competing products, according to Thadani, and RHEV is a lot less expensive than alternative hypervisor and management tool stacks, he says.
The RHEV hypervisor, being based on KVM (which itself is part of the mainstream Linux kernel), is apparently a lot easier for Red Hat to support than the Xen hypervisor, which was grafted onto the initial RHEL 5 release back in March 2007 to give Red Hat some kind of server virtualization to peddle. Red Hat says that if an application is certified to run on RHEL, than it is certified to run on RHEV with RHEL Linux guests, and is offering an application binary guarantee to that effect to customers and independent software vendors. So the 3,500 or so applications certified on RHEL 5 will work unchanged with RHEL running atop KVM - no testing required. It is not clear what guarantee Red Hat is giving for Windows applications, but Thadani said that, generally speaking, if the software runs on bare metal, it runs on RHEV. (Whether you are deploying RHEL or Windows applications, you'd be a fool not to test before deploying.)
KVM, and therefore RHEV, does require the VT-d or AMD-V virtualization extensions in modern Xeon or Opteron processors to work, however. So forget about using RHEV on that old 32-bit iron and maybe even some of that dusty 64-bit stuff in the data center.
The RHEV hypervisor weighs in at under 100 MB in terms of memory footprint on the server, fatter than the 64 MB goal set back in February. The hypervisor can span up to 96 cores and 1 TB of main memory on a single server. The guest VM configurations on top of the hypervisor can have up to 16 virtual CPUs and up to 64 GB of main memory allocated to them. By comparison, VMware's vSphere 4.0 Enterprise Edition, which includes the new ESX Server 4.0 hypervisor, can only span up to 64 cores and 512 GB on the host, and guest VMs can only span 8 virtual CPUs and 255 GB of memory (not 256 GB, I know, it is weird). Microsoft's Windows Server 2008 R2 Hyper-V hypervisor can only span to 48 cores, but can address up to 1 TB of memory. Guest VMs on Hyper-V running Windows can span 4 virtual CPUs, but Linux guests can only see a maximum of one core; memory for either type of guest VM can go up to 64 GB.
No word on when other Linuxes or other x64-based operating systems might be supported on the RHEV hypervisor.
Red Hat knows that it still needs to add storage live migration features to RHEV, but otherwise says it can go toe-to-toe with VMware. (Although the VMware and KVM hypervisor formats are incompatible, so you can't just live migrate VMs from one hypervisor to the other.) Microsoft's Hyper-V is missing memory overcommit (which allows for memory thin provisioning for VMs) and storage live migration as well, features that ESX Server has, but also is missing a system scheduler and power management features, which both RHEV and ESX Server have.
In a related announcement, VMLogix, which has created VM jukeboxing software for ESX Server and Xen hypervisors, said that it would be supporting RHEV with its LabManager tool. The company says that it will have the support ready by the end of the year. The VMLogic LabManager was tapped by Citrix Systems back in February as an add on for the Essentials add-on tools for managing XenServer and Hyper-V hypervisors and their VMs, and was extended to manage images running on Amazon's EC2 compute cloud back in June. ®