How does that intervene with Nutanix Protection Domain operations? PD is based on snapshots that are taken at a vDisk level.

This behavior is common across all storage vendors that provide the ability to take storage snapshots in ESXi environments This is described in detail in the VMware KB article - VMware KB-2147276 Since VMware does not provide a mechanism to know when the in-memory updates to the delta disk header are flushed to disk, it is possible that the storage snapshot taken of the VM at this point may be inconsistent. Storage level snapshots happen at the hardware disk level. Similarly, a synchronous or asynchronous replica of VMFS file system might not contain all header changes as they might have not been flushed at the moment replication of underlying LUN was stopped. If the storage snapshot used to restore a VM was taken before the snapshot header changes were flushed to disk, then delta disk metadata on the restored VM is not consistent. Storage snapshot operations and storage replications are transparent to ESXi hosts. Updates to the header of the delta disks happen in memory as required and the changes are written to disk only upon certain events such as snapshot consolidation or when the delta disk is closed. The delta disk metadata in-memory of vSphere host includes the delta disk header.

If a virtual machine is running off of a snapshot, it is making changes to a child or sparse disk also called delta disk. What are the limitations of VM level snapshot in a Nutanix cluster?įirst, let’s take a look at what are some of the interesting events that occur during the snapshot operation and its presence: It is not an answer to all prayers as, just like anything, it has its limitations. It gives peace of mind and boosts confidence. It is a quick and easy way to roll back recent changes as if nothing has ever happened. We love our VM level snapshots on VMware ESXi.

X-Ray Performance & Reliability Tests 22.NCM Intelligent Operations (formerly Prism Pro/Ultimate) 414.

Snapshot consolidation