To perform operations such as restoring or cloning, as a best practice, you must back up the data on the Replica nodes in the Replica Network.

Backing up the Replica node data lets you save the data. If an operation fails, you can restore the lost or corrupted data.

Prerequisites

  • Verify that you have the deployed blockchain ID information.
  • Familiarize yourself with the backup and restore consideration for your VMware Blockchain nodes. See VMware Blockchain Node Backup and Restore Considerations on vSphere.
  • Verify that you have access to the latest version of VMware Blockchain.
  • Identify the following details from the VMware Blockchain Orchestrator output directory, /home/blockchain/output.

    Blockchain ID

    consortium ID

    Current blockchain version

    Replica node IP address

    Client node IP address

    VMware Blockchain vmbc user password for all the Replica and Client node VMs

  • If the Concord operator containers were deployed, verify that the Concord operator container is running. See Instantiate the Concord Operator Container for vSphere.

Procedure

  1. SSH into the VMware Blockchain Orchestrator appliance.
  2. Enter the login credentials for the blockchain user account.
  3. Navigate to the /home/blockchain directory.
  4. Stop all the applications that invoke connection requests to the Daml Ledger.
  5. Stop the Replica nodes.
    curl -X POST 127.0.0.1:8546/api/node/management?action=stop
  6. Verify that all the containers except the agent and deployed Concord operator container are running on the selected Replica node.
    sudo docker ps -a

    If the sudo docker ps -a command shows that some containers, with the exception of agent and deployed Concord operator container, are still running, rerun the command or use the sudo docker stop <container_name> command to stop the containers.

  7. Check that all the Replica nodes are stopped in the same state.

    Verifying whether the LastReacheableBlockID and LastBlockID sequence number of each Replica node stopped helps determine if any nodes are lagging. As best practice, check if the LastReachableBlockID and LastBlockID are same for at least five Replica nodes and can be sources for recovery.

    If there is a lag when you power on the Replica Network, some Replica nodes in the state-transfer mode might have to catch up. Otherwise, it can result in a failed consensus and require restoring each Replica node from the latest single copy.

    image=$(docker images --format "{{.Repository}}:{{.Tag}}" | grep "concord");docker run --rm --entrypoint="" --mount type=bind,source=/mnt/data/rocksdbdata,target=/concord/rocksdbdata $image /concord/kv_blockchain_db_editor /concord/rocksdbdata getLastBlockID
    image=$(docker images --format "{{.Repository}}:{{.Tag}}" | grep "concord");docker run --rm --entrypoint="" --mount type=bind,source=/mnt/data/rocksdbdata,target=/concord/rocksdbdata $image /concord/kv_blockchain_db_editor /concord/rocksdbdata getLastReachableBlockID

    The <image_name> is the Concord-core image name in the blockchain.

    vmwaresaas.jfrog.io/vmwblockchain/concord-core:1.8.0.0.53

  8. Back up the data on each of the Replica nodes.
    sudo tar cvzf <backup_name> /mnt/data/rocksdbdata 
    #For large data 
    cd /mnt/data/
    sudo nohup tar cvzpf db-backup.tar.gz /mnt/data/rocksdbdata & 
    sudo tail -f nohup.out 
    #Wait for the tar to complete

    The <backup_name> must end in .tar.gz. For example, db-backup.tar.gz.

    The large data backup command might time out due to SSH inactivity. Incrementally rerun the command.

  9. Start all the applications that invoke connection requests to the Daml Ledger.
  10. Start all the Replica nodes in the Replica Network.
    curl -X POST 127.0.0.1:8546/api/node/management?action=start 
  11. Start all the Client nodes.
    curl -X POST 127.0.0.1:8546/api/node/management?action=start

What to do next

If there is a failure or you want to clone a deployment, you can restore it from the backup data. See Restore Replica Nodes from the Backup Data on vSphere.