Recently I was looking into clustering Operations Manager 2007 and sizing the RMS (root management server) cluster disk resource came up. There’s very little documentation on this cluster resource disk and how to size it.
After some research I found that this cluster disk resource stores the Health service state cache. The size of this cache will depend on how many MPs you have, among other things. If you are currently using SCOM 2007, you can look at the Health Service State directory on your RMS server to see how large it is.
A good starting place would be in the 2GB to 5GB range. Storage is cheap these days, so I’d err on the larger size to avoid possible problems down the road. Remember, this cluster resource is NOT the Operational Database which is stored in SQL and can be many 10s of GB.