Replication Partners and How Replication Works

NOTE:

Replication partners can be referred to differently depending on which type of replication is being used. The following describes the different types of replication partners:

  • For snapshot replication: Group partners
  • For synchronous replication: Pool partners
  • For HPE Cloud Volumes (CV) replication: Replication store on the HPE CV portal
    NOTE:

    Replicating encrypted volumes to HPE CV requires release 5.0.6.x or later.

You can configure arrays to have up to fifty snapshot replication partners. Synchronous replication allows only one pool partner. Snapshot and synchronous replication are both automatic, based on the protection schedules assigned to the volume or volume collection.

Replication partners can be reciprocal, upstream (the source of replicas), or downstream (the receiver of replicas) partners. You can have several upstream arrays that replicate to one downstream partner. For synchronous replication, pool partners are created automatically after replication is configured.

When you enable replication of a volume for the first time, the entire data set on the volume at the time of the snapshot is replicated from the original array group (upstream) to the destination replication partner (the downstream array group). Subsequent updates replicate the differences between the last replicated snapshot on the upstream partner to the downstream partner.

It is recommended that you configure the snapshot retention count on the replica (downstream) array group to at least the number of snapshots on the upstream array group, matching the frequency of snapshots.

NOTE: In the majority of array operating system releases, by default, the replication partner retains only two snapshots for each replica volume in the volume collection if configuration is not adjusted.

Replication partners can use different access protocols. One of the partners can be an iSCSI array and its replication partner can be a Fibre Channel array.

Snapshot collections are replicated in the order that the collections were taken. Once replication is caught up, the upstream and downstream replication partners only retain as many snapshots as set in the retention criteria. The system deletes pending snapshot collections that exceed the retention criteria.