Question;
Have you tested HP NetRAID 1M for clustering? HP is saying that model 2M, 4M are the only supported. Because If I'm going to use 1M, my setup would be 2 each for the server where one card is connected to my internal drives and the other one is connected to the external storage. Two Netraid 1m is cheaper than Netraid 2M. Cost effective, I believe. :)
Answer;
See my last answer on RAID Adapters. To answer this directly, No I haven't tested this card.
However, Cost Effective does not mean "Easy to Implement" or "Easy to Troubleshoot". Going with an Internal RAID card is pushing it but as long as the vendor supports the config, you can get help.
Going with an Internal RAID card that the vendor doesn't support in the configuration you are wanting to use is asking for trouble. You are on your own when it breaks and that is not a good place to be when you have 50 (or 500) users breathing down your neck :)
Leon