Nutanix Architecture and Concepts Flashcards

What is Nutanix Erasure Coding (EC-X) and when is it most beneficial?

Answer: A RAID-like technique that reduces storage overhead for cold data by encoding it across nodes instead of full replicas

EC-X uses a RAID-like stripe across nodes to provide data redundancy with less storage overhead than full RF2/RF3 replication, ideal for cold or infrequently accessed data.

In Prism Central, what does the 'X-Play' feature provide?

Answer: Automated playbooks that trigger actions based on events or alerts

X-Play is Nutanix's automation engine in Prism Central that lets administrators create playbooks to automatically respond to alerts and events with predefined actions.

How does Nutanix achieve storage locality for VM I/O?

Answer: By preferentially storing a VM's data on the same node where the VM is running to minimize network traffic

Nutanix's data locality principle ensures that data written by a VM is preferentially stored on the same node's disks, reducing cross-network I/O for read operations.

What happens to data locality when a VM is vMotioned (live migrated) to another node in Nutanix?

Answer: Data remains on the original node; Nutanix migrates it opportunistically in the background based on access patterns

After a live migration, the VM reads data remotely from the original node, and Nutanix opportunistically migrates the data to the new node in the background to restore locality.

Which Nutanix storage feature allows multiple VMs to share a single vDisk efficiently by storing only unique blocks?

Answer: Linked Clones via thin-provisioned snapshots

Nutanix uses a redirect-on-write snapshot mechanism to create space-efficient linked clones where VMs share a base vDisk and only unique changed blocks are stored per VM.

What is the Nutanix 'Medusa' service responsible for?

Answer: Running Cassandra queries on behalf of other services acting as an abstraction layer

Medusa is a metadata abstraction layer that provides a unified API for other Nutanix services to access Cassandra metadata without directly managing distributed database connections.

In Nutanix AHV networking, what is a 'Virtual Switch' and how does it differ from a traditional vSwitch?

Answer: It is an Open vSwitch-based distributed virtual switch that spans all AHV nodes and is managed centrally through Prism

AHV uses Open vSwitch (OVS) as a distributed virtual switch managed centrally through Prism, providing consistent network policy across all nodes without per-host configuration.