If the dataset it fits on one node - good. You might still be missing out on reliability (should that node fail or just plain restart). Simple catalogs and/or

If the dataset it fits on one node - good. You might still be missing out on reliability (should that node fail or just plain restart). Simple catalogs and/or web pages search usually fit in RAM, so the advice of disk:ram becomes less relevant, also the type of drive would be mostly irrelevant.