vDisk

In the Ultra Transcenders books

NCP-MCI-7.5

Each book explains vDisk in context, with comparison tables and the common traps.

Terms in this definition

• AOS

  Software that runs inside the Nutanix Controller VM on the hypervisor and delivers the platform's functions. Joining a cluster requires a node to pair it with a hypervisor in a supported combination.

• Virtual machines

  Infrastructure-as-a-service compute giving complete control of the operating system, making it a fit for lift-and-shift moves and for software relying on OS-level pieces like COM.

• Volume

  Holds non-tabular files sitting in cloud storage under Unity Catalog governance, addressed as /Volumes/<catalog>/<schema>/<volume>. A volume can be external or managed, and WRITE VOLUME or READ VOLUME decide who may use it.

• Storage container

  Raw capacity on a vVols-capable array, presented through its VASA provider and shown in vCenter as a vVols datastore.

• CVM

  A VM required on the hypervisor of every node in a Nutanix cluster, with AOS as its operating system. Every one needs a static IP address of its own.

Related terms

• Fixed provisioning

  In Storage Spaces, the virtual disk claims all its capacity from the pool straight away; the opposite of thin provisioning.

• Flash mode

  Favours SSD for a chosen VM, volume group or vDisk, which keeps data that is sensitive to latency out of cold storage. No hot tier space is reserved, and the ceiling is 25 percent of the SSD tier.

• Inline erasure coding

  Creates erasure coding strips straight away instead of waiting until data turns write cold, within one vDisk or across several. Turned on with nCLI, it is advised by Nutanix only for Object storage containers.

• Live vDisk migration

  Relocating the vDisk of a running VM to a different storage container, perhaps to change data reduction or replication factor. A VM under a storage policy cannot do this.

• PCI

  Guests without VirtIO drivers can still use AHV's virtual disk bus of this name, which stays for compatibility. The name also refers to the physical hardware bus standard.

• Prism Central Allocation and Consumption

  Reports how each service was given its resources, the vDisk capacity of every VM, and vCPU and memory trends. It is a tab in the Prism Central Management area.

• Recycle Bin

  Retains deleted vDisk and configuration data for as long as 24 hours and is enabled by default on a cluster. A restore needs Nutanix Support, and RF1 containers are excluded.

• snapshot

  Captures a VM's disk state, power state, settings and, if requested, memory at a moment in time, using one delta disk per virtual disk. Snapshots should not be relied on as backups.