Recovering from a Longhorn Backup without System Installed

This command gives users the ability to restore a backup to a raw image or a qcow2 image. If the backup is based on a backing file, users should provide the backing file as a qcow2 image with --backing file parameter.

  1. Copy the yaml template: Make a copy of examples/restore_to_file.yaml.template as e.g. restore.yaml.

  2. Set the node which the output file should be placed on by replacing <NODE_NAME>, e.g. node1.

  3. Specify the host path of output file by modifying field hostpath of volume disk-directory. By default the directory is /tmp/restore/.

  4. Set the first argument (backup url) by replacing <BACKUP_URL>, e.g. s3://<your-bucket-name>@<your-aws-region>/backupstore?backup=<backup-name>&volume=<volume-name>.

    • <backup-name> and <volume-name> can be retrieved from backup.cfg stored in the backup destination folder, e.g. backup_backup-72bcbdad913546cf.cfg. The content will be like below:

      {"Name":"backup-72bcbdad913546cf","VolumeName":"volume_1","SnapshotName":"79758033-a670-4724-906f-41921f53c475"}
      
  5. Set argument output-file by replacing <OUTPUT_FILE>, e.g. volume.raw or volume.qcow2.

  6. Set argument output-format by replacing <OUTPUT_FORMAT>. The supported options are raw or qcow2.

  7. Set argument longhorn-version by replacing <LONGHORN_VERSION>, e.g. v1.3.3

  8. Set the S3 Credential Secret by replacing <S3_SECRET_NAME>, e.g. minio-secret.

    • The credential secret can be referenced here and must be created in the `longhorn-system’ namespace.
  9. Execute the yaml using e.g.:

     kubectl create -f restore.yaml
    
  10. Watch the result using:

    kubectl -n longhorn-system get pod restore-to-file -w
    

After the pod status changed to Completed, you should able to find <OUTPUT_FILE> at e.g. /tmp/restore on the <NODE_NAME>.

We also provide a script, restore-backup-to-file.sh, to restore a backup. The following parameters should be specified:

  • --backup-url: Specifies the backups S3/NFS URL. e.g., s3://backupbucket@us-east-1/backupstore?backup=backup-bd326da2c4414b02&volume=volumeexamplename"

  • --output-file: Set the output file name. e.g, volume.raw

  • --output-format: Set the output file format. e.g. raw or qcow2

  • --version: Specifies the version of Longhorn to use. e.g., v1.3.3

Optional parameters can be specified:

  • --aws-access-key: Specifies AWS credentials access key if backups is s3.

  • --aws-secret-access-key: Specifies AWS credentials access secret key if backups is s3.

  • --backing-file: backing image. e.g., /tmp/backingfile.qcow2

The output image files can be found in the /tmp/restore folder after the script has finished running.


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