Oracle will now support Oracle RAC on VMware

Oracle will now support customers running Oracle RAC on VMware platforms, a change in its support policy that shows less hostility toward the leading server virtualization vendor.

Click for the full support document

According to a document that Oracle posted on its support page this week, it will now accept service requests (often called SRs) for Oracle Real Application Cluster 11.2.0.2 and later releases running on VMware-based virtual servers. The document, entitled “Support Position for Oracle Products Running on VMware Virtualized Environments” (Oracle Support login required), marks a change in Oracle’s support for RAC on VMware. Previously, Oracle claimed that there were “technical restrictions” when running Oracle RAC on VMware, and its support policy kept some Oracle shops from exploring the possibility of combining the two technologies.

Oracle didn’t respond to a request for comment by publication time. Two key employees involved in VMware’s operations also didn’t respond to requests for comment, but one of them, the vice president of the VMware technology alliance at parent company EMC, wrote on his personal blog that he was happy with the change.

“Oracle has moved to a more positive support stance on Oracle 11g RAC on VMware,” Chad Sakac wrote on his Virtual Geek blog. “There are still many caveats, but they seem much more reasonable to me.”

One end user may now consider Oracle RAC on VMware

The news was welcomed by companies such as Navisite, an Andover, Mass.-based hosting provider that runs Oracle RAC but currently not on VMware. Brady Reiter, general manager of enterprise architecture and application strategy at Navisite, said he had heard at this year’s Oracle OpenWorld conference that Oracle might change the support policy for Oracle RAC on VMware.

“It will give us a lot more flexibility,” Reiter said about the change. “We don’t currently run RAC on VMware, really because of the supportability.”

Reiter said running Oracle RAC on VMware-based systems could give Navisite’s data center more scalability and flexibility, and he plans to look into a possible deployment. Currently, Navisite doesn’t run any Oracle database products on VMware, and Reiter said he would want to study the potential licensing changes with Oracle if the company does decide it wants to go in that direction.

“One of the things we always have to look at with databases on VMware is the licensing policy, just to make sure that we and our clients aren’t incurring extra licensing expenses,” he said. “There is a concern that we may have to license every physical box that the virtual server may touch, so that is something I would have to look into.”

Consultant: Change in Oracle RAC on VMware policy was long time coming

I’m confident that Oracle thinks this will help them sell more RAC. I would be surprised if Oracle’s motivation for this was anything other than financial.

Dave Welch, CTO, House of Brick

First was the so-called “clock drift” issue, which could happen when running Oracle RAC on VMware on top of Linux. Simply put, older versions of the Linux kernel weren’t designed for server virtualization. As a result, the way that the physical hardware kept time could get out of sync with the way the virtual machine guest running Oracle RAC kept time. The timing mix-up could cause table corruption, according to Oracle.

Customers also heard that Oracle was worried about application performance brownouts when running Oracle RAC on VMware. In particular, there were concerns that if VMware didn’t provide the same level of hardware resources that the full physical server would, then RAC could start shutting down virtual machines and cause a brownout.

Welch said that neither of those issues are valid any longer. Regarding clock drift, newer Linux kernels perform time sync, as does Oracle Database 11g R2 and VMware tools. And Welch said he never saw brownouts happen in live environments.

“I’m confident that Oracle thinks this will help them sell more RAC,” Welch said about the policy change. “I would be surprised if Oracle’s motivation for this was anything other than financial.”

This support change applies only to RAC and doesn’t address other support issues around running Oracle on VMware. Oracle still views the use of VMware’s technology as soft partitioning, meaning that a customer must license the entire physical server for Oracle Database even if it is using the software only on one VMware virtual server running within the box. That is in contrast to Oracle’s own Oracle VM hypervisor, which can be configured for hard partitioning so that only certain processors within a box need to be licensed for Oracle Database.

In order to qualify for support from Oracle, any organization running Oracle on VMware that has a performance problem must also be able to show that the problem happened on the native operating system or, according to the support document, “can be demonstrated not to be as a result of running on VMware.”

Mark Fontecchio can be reached at [email protected].