Regardless of the type of data you generate on your VMs, the data has to be backed up and safe. how do you make sure of that? a first step is to understand our basic approaches and how do we guarantee data resiliency. 

The importance of data protection increases as the amount of data generated by your VMs continues to grow at unprecedented rates by expanding your storage pool, adding nodes to your cluster and deploying new Virtual Machines.

To ensure that the data is safe, we have different approaches, here is a brief explanation for each: 

Protection Domain (two types)

1. Protection domain - Asynchronous DR: is a defined group of entities that consists of VMs and Volume groups that are backed up locally on the cluster and can also be replicated on a remote site. 
2. Protection domain - Metro Availability: is a pre-specified and an active storage container in the local cluster linked to an inactive container with the same name on a remote site in which synchronous data replication occurs when metro availability is enabled

Consistency Group
A consistency group is a subset of the entities in a protection domain.

All entities within a consistency group for that protection domain are snapshotted in a crash-consistent manner. For all VMs in a consistency group, a snapshot creates one snapshot for all VMs in the group.

You can configure the consistency group when creating a protection domain

Snapshot
A snapshot is read-only copy of the state and data of a VM or volume group at a point in time.

Time Stream
A time stream is a set of snapshots that are stored on the same cluster as the source VM or volume group.

Remote Site
A remote site is a separate cluster used as a target location to replicate backed up data. You can configure one or more remote sites for a cluster (see Configuring a Remote Site (Physical Cluster) orCloud Connect (AWS and Azure) ).

Replication
Replication is the process of asynchronously copying snapshots from one cluster to one or more remote sites. Several replication scenarios are supported (see Protection Strategies).

Schedule
A schedule is a property of a protection domain that specifies the intervals to take snapshots and how long the snapshots should be retained. (Schedules are set up when configuring a protection domain.) A schedule optionally specifies which remote site or sites to replicate to.

Related Entities
Related entities are the VMs and volume groups that are associated with the entities that you want to protect. The association can be direct (in the form of direct hypervisor attachment or in-guest iSCSI) or transitive (if a volume group is attached to two VMs, then the VMs are considered to be related to each other).