Cloudera Manager and monitoring systems require more resources than a regular deployment for big clusters with a large number of nodes. To support this, now COD supports a fast gp2 storage when you choose a gateway node of HEAVY type.
This is available starting in COD v1.24 and you do not need to upgrade to a higher version of COD to benefit from this feature.
Try out CDP Operational Database for free with Test Drive (no cloud account or setup is needed).