Target instance: The instance from which you are restoring from backup.
Destination instance: The instance on which you are restoring from backup.

Checklist before proceeding to restore Tamr from a backup

• You have an existing Tamr installation of identical major and minor version. See Installation. The patch version does not need to match exactly. For information about patches, see Upgrading Tamr.
• You have a backup file created on the target instance. For information, see Backup and backups (v1).
• The location of the backup files needs to be in a place from which the destination instance can read them, and inside of the TAMR_UNIFY_BACKUP_URI for the destination instance.
• Tamr functional user, such as tamr, has read and write permissions on the TAMR_UNIFY_BACKUP_URI for the destination instance.
• The destination instance must contain a clean Tamr installation.

Note: Restoring Tamr from a backup deletes all data in the destination instance and automatically restarts Tamr.

Restoring from a Backup

Before you begin, ensure that you have met the checklist requirements.

To Restore an Instance from a Backup:

1. On the destination instance, restore Tamr from a backup by reading a backup specified in the POST body. Run:
   POST /v1/instance/restore
   Tamr is unavailable during a restore process. Also see backups (v1).

2. Poll for the status of the restore operation until status.state=SUCCEEDED is returned. Run:
   GET /v1/instance/restore. Also see instances (v1).

Restoring from Backup on Another Instance

Once you create a backup on the target instance and then restore from it on one destination instance, you may also want to restore from the same backup files on another destination instance. Two situations are possible and they depend on the location in which the backup files are stored.

• If you are using a distributed filesystem to store the backup files, you can restore from the backup to any destination instance without having to physically transfer backup files.

• If you are using a server filesystem, create a TAR of the backup so you only have to transfer one file, copy this backup file to the destination instance inside of the TAMR_UNIFY_BACKUP_URI, untar the file to the correct location, and trigger a restore process. For details, see Restore.