Convert standalone standby DB to a Standby RAC

OS: RHES 4
DB: 10.2.0.1

We currently have a test environment that has a successful implementation of DataGuard in fast_start failover mode. The primary DB is a 2 node RAC and the physical standby is a standalone server. What we want to do know is test both the primary and standby servers in RAC mode.

Is it possible to convert a standalone server to RAC once the standalone has been setup as a physical standby server? Do we have to drop the standalone DB and set it up as RAC and then convert it back to a standby server? I've looked at the documentation and read how to convert a standalone DB to a RAC db but it doesn't describe how it should be done if the standalone server is in a dataguard setup.

Thanks,

Mark

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