Enabling geo-replication

Prerequisites

Two backup storage clusters are deployed, as described in Provisioning backup storage space.
Before you configure geo-replication for the secondary cluster, delete all of its registrations, as explained in Deleting registrations.
All storage clusters are updated to the latest version.
All storage clusters can reach each other via domain names on TCP port 44445.
Each storage cluster can reach itself via its own domain name on TCP port 44445. This is especially important if the clusters are situated behind NAT.

To set up geo-replication between two storage clusters

Admin panel

On the cluster that will be configured as secondary, go to Storage services > Backup storage > Geo-replication. Click the copy icon next to the UID field to copy its UID to clipboard.
On the cluster that will be configured as primary, go to Storage services > Backup storage > Geo-replication. Click Configure replication, and then do the following in the Configure replication window:
1. Specify external DNS names for the primary and secondary backup storage clusters, and then paste the UID of the secondary cluster. Click Next.
  
  It is recommended to provide DNS names different from those of backup storage registrations. Otherwise, once you reconfigure the backup storage DNS name, the clusters will be unable to communicate and geo-replication will be stopped. If you cannot provide a dedicated DNS name, specify the DNS name used for backup storage creation.
2. Specify the following information for your Acronis product:
  - The URL of the cloud management portal (for example, https://cloud.acronis.com/) or the hostname/IP address and port of the local management server (for example, http://192.168.1.2:9877)
  - The credentials of a partner account in the cloud or of an organization administrator on the local management server
3. Click Configure.
The primary cluster is now configured and ready to be connected to the secondary one, which needs to be configured next. The configuration file of the primary cluster will be automatically downloaded to your local server. Alternatively, you can do it manually by clicking Download configuration file.
On the secondary cluster, click Configure replication, and then do the following in the Configure replication window:
1. Select the Secondary cluster configuration type.
2. Upload the configuration file of the primary cluster from your local server.
3. Click Configure.
The secondary cluster is now also configured and ready to be connected to the primary one.
Back on the primary cluster, click Connect to enable replication between the two datacenters.

Command-line interface

On the cluster that will be configured as secondary, run vinfra service backup geo-replication show to learn its UID. For example:

# vinfra service backup geo-replication show
+-------+-----------------------------+
| Field | Value                       |
+-------+-----------------------------+
| self  | address: no address         |
|       | datacenter_uid: e63a6738<…> |
+-------+-----------------------------+

On the cluster that will be configured as primary, run vinfra service backup geo-replication primary setup, using the DNS names for the primary cluster, as well as the DNS name and UID of the secondary cluster. Additionally, specify the URL of the cloud management portal or the hostname/IP address and port of the local management server and the account credentials for the registration. For example:
```
# vinfra service backup geo-replication primary setup --primary-cluster-address 
primary.example.com \
--secondary-cluster-address secondary.example.com --secondary-cluster-uid e63a6738<…> \
--username account@example.com --account-server https://cloud.acronis.com --stdin
```
On the primary cluster, run vinfra service backup geo-replication primary download-configs to generate the configuration file of the primary cluster. For example:
```
# vinfra service backup geo-replication primary download-configs --conf-file-path primary_dc.conf
```
Move the configuration file of the primary cluster to the secondary cluster using the standard Linux command-line tool. For example, by using scp:
```
# scp primary_dc.conf <secondary_cluster_IP_address>:/root/primary_dc.conf
```
On the secondary cluster, run vinfra service backup geo-replication secondary setup to upload the configuration file of the primary cluster. For example:
```
# vinfra service backup geo-replication secondary setup --dc-config-file primary_dc.conf
```
If for some reason, you need to cancel geo-replication, run vinfra service backup geo-replication primary cancel on the primary cluster and vinfra service backup geo-replication secondary cancel on the secondary cluster.
On the primary cluster, run vinfra service backup geo-replication primary establish to establish a connection between the primary and secondary clusters. For example:
```
# vinfra service backup geo-replication primary establish
```