Using FlashArray Volume Snapshots as a State Snapshot Transfer method

Potential Galera Cluster nodes can be provisioned through the use of volume snapshots. A volume snapshot is considered a manual physical SST as there is no automation for the use of this method.

1. Using the MySQL command line client execute the following command on any node joined to the cluster.

   
   SHOW GLOBAL STATUS LIKE 'wsrep_%'; 
   

2. Analyze the output and identify the following variable.

   
   +-------------------------------+-------------------------------------------------------------------------------------------------+
   | Variable_name                 | Value                                                                                           |
   +-------------------------------+-------------------------------------------------------------------------------------------------+
   | wsrep_local_state_comment     | Synced                                                                                          |
   +-------------------------------+-------------------------------------------------------------------------------------------------+
   

   The wsrep_local_state_comment needs to have the value Synced for the node to be valid donor for the volume snapshot.

   Note:

   It is possible to perform Volume Snapshot SSTs for databases that utilize layouts for different data, binary and transaction log directories, or separate volumes for database/schema files. All volumes for the instance must have a snapshot created as a part of a protection group. Restoring the copied volumes will require the relevant variables to be set in the option file prior to starting the joiner node.

   The following assumptions are made for these instructions:

   • The MySQL/MariaDB donor instance is deployed on a single FlashArray volume.
   • The Galera Cluster has been initialized with at least one node member.
   • The MySQL/MariaDB joiner has been installed and has a single FlashArray volume connected to it. MySQL/MariaDB must not be started and the volume must not be mounted.

   Note:

   Copying a volume from snapshot can be done by copying the snapshot to a new volume or overwriting an existing volume.

   Volume snapshots can also be replicated between arrays through the use of asynchronous replication.

   The Clone Plugin must be disabled when cloning nodes volumes using storage snapshots. If the clone plugin is enabled then the donor and joiner will attempt to overwrite any existing data on the joiner to place it in the correct state.

   To disable the clone plugin use the command.

   
   UNINSTALL PLUGIN clone;
   

   The installed plugins can then be checked using the command.

   
   SHOW PLUGINS;