Architectures for computing clusters with enhanced scalability and fault isolation capabilities are described. The enhanced capabilities are enabled by partitioning hosts of the clusters into multiple storage domains of the cluster. Each of the hosts includes processing and storage resources. The resources are logically partitioned into a processing layer and a storage layer of the cluster. The processing layer includes a virtualized processing resource for each of the storage domains. The storage layer includes a virtualized datastore for each of the storage domains. The processing layer provides users with access to virtualized machines (VMs). The storage layer provides the VMs with access to virtualized datastores of the associated storage domain. The aggregated resources of the host computing devices within the cluster may be employed to instantiate the processing layer and the storage layer of the cluster.