Should you decide to run Cognos on an "Unsupported Environment", IE. on software/hardware that is not listed on the supported env page (Supported Env link: https://www-304.ibm.com/support/docview.wss?uid=swg27014782), then make sure you are aware of the following "Unsupported Environment Policy for Cognos".
http://www-01.ibm.com/support/docview.wss?uid=swg27014892
Basically the just of it is, should you encounter an "issue/error" IBM has the right to ask you to reproduce the behavior on a supported platform/software.