External Replication¶

Creating Async Replicas¶

Replicating a volume or a filesystem to a remote system (mirroring) can be done by calling the replicate_entity shortcut:

>>> pool = primary.pools.create()
>>> vol = primary.volumes.create(pool=pool)
>>> remote_pool = secondary.pools.create()
>>> replica = primary.replicas.replicate_entity(vol, link=link, remote_pool=remote_pool)

The default behavior for ReplicaBinder.replicate_entity() is to create the remote entity (receiving a remote pool as input). You can also use an existing remote entity through the ReplicaBinder.replicate_entity_use_base() shortcut:

replica = primary.replicas.replicate_entity_use_base(
    local_entity,
    link=link,
    local_snapshot=snap,
    remote_snapshot=remote_snap)

Replication creation requires the following arguments to be provided:

A local entity (e.g. volume, filesystem or consistency group)
A link (an instance of infinisdk.infinibox.link.Link, representing the network link to the remote system)

As for the remote entity, it depends on the scenario being used to create the replica:

Using a base snapshot (_use_base) requires a remote and local snapshots
Creating a new entity on the remote side (_create_target or default) requires the remote pool to be provided
Creating over an existing, formatted target (_existing_target) requires the remote target to be provided via remote_entity parameter

Replicating Consistency Groups¶

Creating a CG replica is also straightforward, and is done via the replicate_cons_group method:

>>> cg = primary.cons_groups.create(pool=pool)
>>> replica = primary.replicas.replicate_cons_group(cg, link=link, remote_pool=remote_pool)

Creating Synchronous Replicas¶

Creating synchronous replicas is done by specifying "SYNC" for the replication_type parameter during replica creation:

>>> pool = primary.pools.create()
>>> vol = primary.volumes.create(pool=pool)
>>> replica = primary.replicas.replicate_entity(
...     vol, link=link,
...     replication_type="SYNC", remote_pool=remote_pool)

Changing Replication Type¶

Changing the type of the replication to SYNC / ASYNC can be done by calling to change_type_to_sync / change_type_to_async respectively. The replica must not be in INITIALIZING state. For example:

>>> async_replica.change_type_to_sync()
>>> assert async_replica.is_type_sync()
>>> async_replica.change_type_to_async()
>>> assert async_replica.is_type_async()