Request for advice on use of RTC in complex tests

System Verification Test (SVT) and customers frequently need to test Rational Team Concert in complex deployments emulating production environments. I would like guidance on avoiding invalid or problematic situations.

I understand there is a general rule for production deployments, "Two repositories with the same SCM contents are not allowed and are not supported." One starting point for repeated or comparative testing is a tar file created with repotools which is exported from one Jazz repository and then imported to more than one Jazz server (either at separate URLs or sequentially.) The repository contents and repo id are identical but each repository is in a distinct database.

The first situation I want to ask about might come up when running the same test on the same client platform against servers on different platforms. Would there be any danger in simultaneously bringing up two instances of RTC client on the same client machine, each in its own Eclipse workspace, each connecting to one of these repositories at its unique URL?

The second situation might come up when running a series of tests on the same client machine against servers which originate from the same tar file and are available sequentially at the same URL. Is it necessary to switch the RTC client to a different Eclipse workspace for each new server instance in this case?

I believe Dmitry Karasik has some answers for me.