Multiple storages for backups

You can define several storage locations for backups in the Operator. However, previously you were limited to only a single storage for point-in-time recovery, because Percona Backup for MongoDB (PBM) couldn’t maintain oplog consistency across multiple storages. Also, you had to wait for the Operator to reconfigure the cluster and sync metadata after you make the next backup or a restore to a different storage.

This behavior is improved. The Operator differentiates the storages as the main storage and profiles. The difference between them is that the Operator uses the main storage to save both backups and oplog chunks for point-in-time recovery. Profiles are used only for backups. This is done for data consistency and to enable point-in-time recovery from a backup on any storage.

Define the main storage

When you configure only one storage, the Operator automatically uses it as the main one until you add more. When you add another storage, you must mark which one is the main using the main: true flag in the deploy/cr.yaml Custom Resource manifest.

storages:
  s3-us-west:
    main: true
    type: s3

Note that you can have only one main storage. All other storages are added as profiles.

To check the list of profiles, connect to the database Pod and run the pbm profile list command. For example, for the cluster cluster1, the command looks as follows:

$ kubectl exec cluster1-rs0-0 -c backup-agent -- pbm profile list

You can run other profile management commands in the same way.

Change the main storage

You can change the main storage by reassigning the main:true flag for another one. The Operator then:

• Resyncs the metadata for the new main storage
• Deletes the profile for it
• Adds the previous main storage as a profile

Pass storage configuration via restore objects

Usually you define the storage configuration within the deploy/cr.yaml Custom Resource manifest. You can also pass it to the Operator within the backupSource option of a Restore object. For example, when you restore the failed site after a disaster. The Operator then checks the current configuration and:

• If there is no storage configured there, it uses the one from the Restore object as the main storage until you define it in the deploy/cr.yaml file.
• If the deploy/cr.yaml Custom Resource manifest has the storage configured and it differs from the one from the Restore object, the Operator adds this storage as a profile.

Backup metadata resync

The Operator resyncs the metadata in the following cases:

For the main storage:

• When the main storage changes
• When you manually start a resync using the pbm config --force resync

For the profile storage:

• When you start a restore from a backup on a profile
• When you manually resync the metadata on a profile using the pbm profile sync <storage-name> command

For the main storage and profiles:

• When you added an annotation percona.com/resync-pbm=true to the deploy/cr.yaml Custom Resource manifest.

Note that resync is a resource consuming task and we don’t recommend to run it manually. Read more when you need to run it in PBM documentation

The improved support for multiple backup storages brings the following benefits:

• Enables you to make a point-in-time recovery from any storage with guaranteed data consistency
• Reduces the load on the cluster for reconfiguration when the storage for a next backup changes

Upgrade considerations

You must specify the main storage during the upgrade. If you use a single storage, it will automatically be marked as main in the Custom Resource manifest. If you use multiple storages, you must define one of them as main.

The following command shows how to set the s3-us-west storage as the main one:

$ kubectl patch psmdb my-cluster-name --type=merge --patch '{
    "spec": {
      "crVersion": "1.20.0",
      "image": "percona/percona-server-mongodb:7.0.18-11",
      "backup": {
        "image": "percona/percona-backup-mongodb:2.9.1",
        "storages": {
          "s3-us-west": {
            "main": true
          }
        }
      },
      "pmm": {
        "image": "percona/pmm-client:2.44.1"
      }
    }
  }'

For more information about the upgrades, see the Update documentation

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Last update: 2025-05-20