NCS-Core flashcards
NCS-Core · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- CVM role
- The Controller VM runs on each node and serves all storage I/O for that node's local disks through the distributed storage fabric, presenting storage to the hypervisor.
- Stargate service
- The DSF data I/O manager running on each CVM; it handles read/write requests and serves extent groups from local physical media.
- Cassandra in AOS
- A distributed metadata store on the CVMs that tracks vDisk-to-extent mappings and cluster metadata, enabling data locality lookups.
- Prism Element vs Central
- Prism Element manages a single cluster; Prism Central aggregates multiple clusters and enables categories, policies, and centralized lifecycle management.
- AHV hypervisor
- Nutanix's native KVM-based hypervisor; it runs VMs and hosts the CVM as a privileged VM with direct disk access.
- Metadata ring quorum
- Cluster metadata requires an odd number of nodes for quorum; a minimum three-node cluster provides resilience against a single node failure.
- Foundation imaging
- The tool that images bare-metal nodes with AOS and hypervisor bundles and creates the cluster, requiring IPMI access and IP planning.
- Internal cluster network
- Default 192.168.5.0/24 subnet on the CVM backplane used for CVM-to-CVM storage traffic; it must not overlap external subnets.
- NCC health check
- Nutanix Cluster Check runs a suite of health validations; run it after installation and before upgrades to catch configuration issues.
- Storage container RF
- A container setting defining replication factor: RF2 tolerates one node failure, RF3 tolerates two, at the cost of capacity overhead.
- Erasure coding EC-X
- A capacity optimization that stripes data across nodes with parity; requires RF2/RF3 and is not recommended for latency-sensitive workloads.
- Nutanix Volumes
- A service exposing block storage to external hosts via iSCSI, using vDisks managed by the cluster.
- Protection domain
- A grouping of VMs used for replication and snapshot policies; async replication ships snapshots to a remote cluster.
- Nutanix DR (Leap)
- Disaster recovery using protection policies with RPO/RTO targets and recovery plans for orchestrated failover between clusters.
- Prism Central scale-out
- Prism Central is deployed as a scale-out VM set sized by managed VM count; it must be registered to clusters for centralized features.
- Lifecycle Manager LCM
- Inventories firmware, AOS, hypervisor, and Prism Central versions, then stages and applies upgrades with pre-checks.
- Categories and policies
- Key-value tags applied to VMs and entities; policies use them to automate protection, placement, and reporting at scale.
- Prism REST v3
- RESTful API under /PrismGateway/services/rest/v3/ using JSON bodies and task UUIDs for asynchronous operations, preferred for new automation.
- acli vs ncli
- acli targets Prism-level operations such as VM lifecycle; ncli targets cluster services and host/disk diagnostics.
- CVM log location
- Nutanix service logs such as Stargate and Cassandra reside under /home/nutanix/data/logs on the CVM for troubleshooting.
- Log collector
- A Prism support tool that bundles cluster logs and NCC output for attaching to a support case, speeding escalation.
- Support severity levels
- Cases are classified S1 (critical outage) through S4 (low impact); S1 cases require immediate engagement and log attachment.
- CVM unreachable triage
- Check IPMI console, CVM network configuration, and that the CVM VM is powered on; rebooting the CVM does not lose data.
- Upgrade order
- Typical order is firmware, then AOS, then hypervisor per the compatibility matrix; verify Prism Central compatibility before starting.
- Rolling AOS upgrade
- AOS upgrades one CVM at a time; the cluster stays available but performance may dip during data rebalancing.
- Cluster expansion
- Image the new node with Foundation, then add it via Prism; match AOS and hypervisor versions to the existing cluster.
- Node removal evacuation
- Remove a node gracefully so DSF re-replicates its data; never pull disks from a live node or remove without capacity checks.
- Least privilege RBAC
- Assign roles such as Viewer, VM Admin, or Prism Admin scoped to clusters or projects; avoid shared admin accounts.
- Cluster lockdown mode
- Restricts CVM and host access to reduce attack surface; enable only after validating management access paths.
- Audit log forwarding
- Prism audit logs record user actions; forward them via syslog to a SIEM for retention and compliance evidence.
- API task polling
- Asynchronous API calls return a task UUID; poll the task endpoint until it reports success or failure before proceeding in automation.
- Calm blueprints
- Prism Central feature defining multi-tier application blueprints with variables and runbooks for self-service provisioning and automation.