Appendix A. Advanced Block Storage backup configuration options
Prior to director-deployed installations, the cinder.conf file was used to configured the Block Storage service and the backup service. When a value from cinder.conf does not have a Heat template equivalent, the values can still be passed from director using a custom environment. The values are added to an ExtraConfig section in the parameter_defaults section of a custom environment file (like cinder-backup-settings.yaml).
ExtraConfig provides a method for additional hiera configuration to inject into the cluster on all nodes. These settings are included on a dedicated backup node, for example, if you used ExtraConfig. If you used ControllerExtraConfig instead of ExtraConfig, then those settings would only be installed on controller nodes and not on a dedicated backup node.
You can substitute DEFAULT/[cinder.conf setting] for the setting that would be used in the DEFAULT section of the cinder.conf file. The example below shows how the ExtraConfig and entries appear in a YAML file.
parameter_defaults:
ExtraConfig:
cinder::config::cinder_config:
DEFAULT/backup_compression_algorithm:
value: NoneThe options below provide a sample of the backup-related options.
Table A.1. Block Storage backup service configuration options
| Option | Type | Default Value | Description |
|---|---|---|---|
| backup_service_inithost_offload | Optional | True | Offload pending backup delete during backup service startup. If false, the backup service remains down until all pending backups are deleted. |
| use_multipath_for_image_xfer | Optional | False | Attach volumes using multipath, if available, during backup and restore procedures. This affects all cinder attach operations, such as create volume from image, generic cold migrations, and so forth. |
| num_volume_device_scan_tries | Optional | 3 | The maximum number of times to rescan targets to find volume during attach. |
| backup_workers | Optional | 1 | Number of backup processes to run. Performance gains will be significant when running multiple concurrent backups or restores with compression. |
| backup_native_threads_pool_size | Optional | 60 | Size of the native threads pool for the backups. Most backup drivers rely heavily on this. The value can be decreased for specific drivers that don’t rely on this option. |
| backup_share | Required | Set to HOST:_EXPORT_PATH_. | |
| backup_container | Optional | None | (String) Custom directory to use for backups. |
| backup_enable_progress_timer | Optional | True | Enable (true) or disable (false) the timer to send the periodic progress notifications to Ceilometer when backing up the volume to the backend storage. |
| backup_mount_options | Optional | Comma-separated list of options to be specified when mounting the NFS export specified in backup_share. | |
| backup_mount_point_base | Optional | $state_path/backup_mount | (String) Base directory containing mount point for NFS share. |
| backup_compression_algorithm | Optional | zlib | The compression algorithm to be used when sending backup data to the repository. Valid values are zlib, bz2, and None. |
| backup_file_size | Optional | 1999994880 | Data from cinder volumes larger than this will be stored as multiple files in the backup repository. This option must be a multiple of backup_sha_block_size_bytes. |
| backup_sha_block_size_bytes | Optional | 32768 | Size of cinder volume blocks for digital signature calculation |
