NDMP backup and restore of SmartLink files

You can perform NDMP backup and restore operations on data that has been archived to the cloud.

Backup and restore capabilities with CloudPools data include:

  • Archive SmartLink files when backing up from a cluster
  • Restore data, including SmartLink files, to the same cluster
  • Restore data, including SmartLink files, to another cluster
  • Back up version information with each SmartLink file and restore the Smartlink file after verifying the version compatibility on the target cluster.

With NDMP backup, by default, CloudPools supports backup of SmartLink files that contain cloud metadata such as location of the object. Other details such as version information, account information, local cache state, and unsynchronized cache data associated with the SmartLink file are also backed up.

To prevent data loss when recovering SmartLink files with incompatible versions, you can use the NDMP combo copy backup option to back up SmartLink files with full data. Full data includes metadata and user data. You can use the NDMP combo copy option by setting the BACKUP_OPTIONS environment variable.

When performing an NDMP restore operation on SmartLink files backed up using the combo copy option, you can use one of combo copy, shallow copy, or deep copy restore options to recover SmartLink files. You can specify these options by setting appropriate values to the RESTORE_OPTIONS environment variable:

  • The combo copy restore option restores SmartLink files from the backup stream only if their version is compatible with the OneFS version on the target cluster. If the SmartLink file version is incompatible with the OneFS version on the target cluster, a regular file is restored.
  • The shallow copy restore operation restores the backed up SmartLink file as a SmartLink file on the target cluster if the version check operation on the target cluster is successful.
  • The deep copy restore operation forces the recovery of the SmartLink files as regular files on the target cluster If the version check operation on the target cluster fails.
  • If you do not specify any restore operation, NDMP restores SmartLink files using the combo copy restore operation by default.
  • When you specify multiple restore options, the combo copy restore operation has the highest priority followed by the shallow copy restore operation. The deep copy restore operation has the lowest priority.

In CloudPools settings, you can set three retention periods that affect backed up SmartLink files and their associated cloud data:

  • Full Backup Retention Period for NDMP takes effect when the SmartLink file is backed up as part of a full backup. The default is five years.
  • Incremental Backup Retention Period for Incremental NDMP Backup and SyncIQ takes effect when a SmartLink file is backed up as part of an incremental backup. The default is five years.
  • Cloud Data Retention Period defines the duration that data in the cloud is kept when its related SmartLink file is deleted. The default is one week.

CloudPools ensures the validity of a backed-up SmartLink file within the cloud data retention period. It is important for you to set the retention periods appropriately to ensure that when the SmartLink file is restored from tape, it remains valid. CloudPools disallows restoring invalid SmartLink files.

To check whether a backed-up SmartLink file is still valid, CloudPools checks the retention periods stored on tape for the file. If the retention time is past the restore time, CloudPools prevents NDMP from restoring the SmartLink file.

CloudPools also makes sure that the account under which the SmartLink files were originally created has not been deleted. If it has, both NDMP backup and restore of SmartLink files will fail.