10.3. Preparing to Deploy Geo-replication

Creating Geo-replication Sessions

1. To create a common pem pub file, run the following command on the master node where the key-based SSH authentication connection is configured:

   # gluster system:: execute gsec_create

2. Create the geo-replication session using the following command. The push-pem option is needed to perform the necessary pem-file setup on the slave nodes.

   # gluster volume geo-replication MASTER_VOL SLAVE_HOST::SLAVE_VOL create push-pem [force]

   For example:

   # gluster volume geo-replication Volume1 storage.backup.com::slave-vol create push-pem

   Note

   • There must be key-based SSH authentication access between the node from which this command is run, and the slave host specified in the above command. This command performs the slave verification, which includes checking for a valid slave URL, valid slave volume, and available space on the slave. If the verification fails, you can use the force option which will ignore the failed verification and create a geo-replication session.
   • The slave volume is in read-only mode by default. However, in case of a failover-failback situation, the original master is made read-only by default as the session is from the original slave to the original master.
3. Enable shared storage for master and slave volumes:

   # gluster volume set all cluster.enable-shared-storage enable

   For more information on shared storage, see Section 11.12, “Setting up Shared Storage Volume”.
4. Configure the meta-volume for geo-replication:

   # gluster volume geo-replication MASTER_VOL SLAVE_HOST::SLAVE_VOL config use_meta_volume true

   For example:

   # gluster volume geo-replication Volume1 storage.backup.com::slave-vol config use_meta_volume true

   For more information on configuring meta-volume, see Section 10.3.5, “Configuring a Meta-Volume”.
5. Start the geo-replication by running the following command on the master node:
   For example,

   # gluster volume geo-replication MASTER_VOL SLAVE_HOST::SLAVE_VOL start [force]

6. Verify the status of the created session by running the following command:

   # gluster volume geo-replication MASTER_VOL SLAVE_HOST::SLAVE_VOL status

1. In all the slave nodes, create a new group. For example, geogroup.

   Note

   You must not use multiple groups for the mountbroker setup. You can create multiple user accounts but the group should be same for all the non-root users.
2. In all the slave nodes, create a unprivileged account. For example, geoaccount. Add geoaccount as a member of geogroup group.
3. On any one of the Slave nodes, run the following command to set up mountbroker root directory and group.

   # gluster-mountbroker setup <MOUNT ROOT> <GROUP>

   For example,

   # gluster-mountbroker setup /var/mountbroker-root geogroup

4. On any one of the Slave nodes, run the following commands to add volume and user to the mountbroker service.

   # gluster-mountbroker add <VOLUME> <USER>

   For example,

   # gluster-mountbroker add slavevol geoaccount

5. Check the status of the setup by running the following command:

   # gluster-mountbroker status
   
        NODE    NODE STATUS                  MOUNT ROOT         GROUP              USERS
   --------------------------------------------------------------------------------------- localhost             UP   /var/mountbroker-root(OK)  geogroup(OK)  geoaccount(slavevol)
       node2             UP   /var/mountbroker-root(OK)  geogroup(OK)  geoaccount(slavevol)
   

   The output displays the mountbroker status for every peer node in the slave cluster.
6. Restart glusterd service on all the Slave nodes.

   # service glusterd restart

   After you setup an auxiliary glusterFS mount for the unprivileged account on all the Slave nodes, perform the following steps to setup a non-root geo-replication session.:
7. Setup key-based SSH authentication from one of the master nodes to the user on one of the slave nodes.
   For example, to setup key-based SSH authentication to the user geoaccount.

   # ssh-keygen
   # ssh-copy-id -i identity_file geoaccount@slave_node_IPaddress/Hostname

8. Create a common pem pub file by running the following command on the master nodes, where the key-based SSH authentication connection is configured to the user on the slave nodes:

   # gluster system:: execute gsec_create

9. Create a geo-replication relationship between the master and the slave to the user by running the following command on the master node:
   For example,

   # gluster volume geo-replication MASTERVOL geoaccount@SLAVENODE::slavevol create push-pem

   If you have multiple slave volumes and/or multiple accounts, create a geo-replication session with that particular user and volume.
   For example,

   # gluster volume geo-replication MASTERVOL geoaccount2@SLAVENODE::slavevol2 create push-pem

10. On the slave node, which is used to create relationship, run /usr/libexec/glusterfs/set_geo_rep_pem_keys.sh as a root with user name, master volume name, and slave volume names as the arguments.
    For example,

    # /usr/libexec/glusterfs/set_geo_rep_pem_keys.sh geoaccount MASTERVOL SLAVEVOL_NAME

11. Configure the meta-volume for geo-replication:

    # gluster volume geo-replication MASTER_VOL SLAVE_HOST::SLAVE_VOL config use_meta_volume true

    For example:

    # gluster volume geo-replication Volume1 storage.backup.com::slave-vol config use_meta_volume true

    For more information on configuring meta-volume, see Section 10.3.5, “Configuring a Meta-Volume”.
12. Start the geo-replication with slave user by running the following command on the master node:
    For example,

    # gluster volume geo-replication MASTERVOL geoaccount@SLAVENODE::slavevol start

13. Verify the status of geo-replication session by running the following command on the master node:

    # gluster volume geo-replication MASTERVOL geoaccount@SLAVENODE::slavevol status