https://review.openstack.org/113054
commit 1c8f49bfe9fe3abd713e28922d5551f71228624c
Author: Ronen Kat <email address hidden>
Date: Sat Jul 26 17:06:52 2014 +0300
Add support in Cinder for volume replication - driver approach
This is take #2 for managing replicaiton in Cinder.
This patch provides the foundation in Cinder to make volume
replication available to the cloud admin. It makes Cinder aware
of volume replicas, and allows the cloud admin to define storage
policies (volume types) that will enable replication.
In this version Cinder delegates most the work on replication
to the driver itself.
This includes:
1. Driver exposes replication capabilities via volume type convention.
2. Extend volume table to include columns to support replicaion.
3. Create replicas in the driver, making it transparant to Cinder.
4. Volume manager code to handle API, updates to create_volume to
support creating test replicas.
5. Driver methods to expose per replication functions
Cinder-specs available at https://review.openstack.org/#/c/98308/
Volume replication use-case: Simplified disaster recovery
The OpenStack cloud is deployed across two metro distance data centers.
Storage backends are available in both data ceneters. The backends
are managed by either a single Cinder host or two, depending on the
storage backend requirements.
Storage admin configures the Cinder volume driver to support
replication.
Cloud admin creates a volume type "replicated" with extra-specs:
capabilities:replication="<is> True"
Every volume created in type "replicated" has a copy on both
backends.
In case of data center failure in first data center, the cloud admin
promotes the replica, and redeploy the VMs - they will now run on
a host in the secondary data center using the storage on the
secondary data center.
Implements: blueprint volume-replication
DocImpact
Change-Id: I964852f08b500400a27bff99e5200386e00643c9
From duplicate bug:
Need the documentation related to replication support.
Docs problem :
1. required multi back end support for replication ..?
2. changes required for replication support in cinder.conf file.
3.changes in database tables for replication.
4. replication relation table not present in juno code ..??
5. where to provide info of 2nd storage node ..?
6. from where controller knw which is 1st and 2nd storage nodes .
7.capabilities scheduler .py is not there in juno code ..??
and how it is related to replication support.