No Single Master
Medusa (Distributed Metadata Layer)
Nutanix Complete Cluster stores its metadata(informationon what is stored where) in a distributed metadata layer named Medusa. As more nodes are added to the cluster,the metadata layer also continues to scale.
Medusa stores the metadata on PCIe-based io Memory from Fusion-io, making the metadata accesses faster without limiting the metadata to RAM as is the case in traditional solutions. This allows the cluster to keep rich metadata for advanced functionality without the meta data layer becoming a bottleneck.
This information is from the Project Colossus White Paper, 50-node Scale-out Performance Benchmark that illustrates the power of the Nutanix Distributed File System architecture in enabling linear performance scale-out to deliver 375,000 random write IOPS and over 224 Gbps sequential read bandwidth.