Kubeblocks Backup

Backup KubeBlocks Database Clusters

Overview

KubeBlocks provides data protection through full backups, scheduled backups, and continuous backups (for Point-in-Time Recovery). Backups are managed via the Backup CR or OpsRequest CR, and stored in a configured BackupRepo.

Official docs: https://kubeblocks.io/docs/preview/user_docs/concepts/backup-and-restore/introduction

Backup Methods by Addon

Choosing a Backup Method

• Physical backup (xtrabackup, pg-basebackup, datafile): Portable and self-contained — the backup is a complete copy of the data files stored in BackupRepo. Works on any storage backend. Recommended as the default because it has no infrastructure dependencies beyond BackupRepo.
• Volume snapshot: Leverages the storage layer's native snapshot capability (via CSI). Extremely fast for large databases since it's a copy-on-write operation, but requires a VolumeSnapshotClass and a CSI driver that supports snapshots — not always available, especially in local/dev environments.
• Continuous backup (archive-binlog, wal-archive): Streams transaction logs in real time to enable Point-in-Time Recovery (PITR). Essential for production workloads where you need to recover to any arbitrary point in time, not just the moment of the last full backup.

Pre-Check

Before proceeding, verify the cluster is healthy and no other operation is running:

# Cluster must be Running
kubectl get cluster <cluster-name> -n <namespace> -o jsonpath='{.status.phase}'

# No pending OpsRequests
kubectl get opsrequest -n <namespace> -l app.kubernetes.io/instance=<cluster-name> --field-selector=status.phase!=Succeed

If the cluster is not Running or has a pending OpsRequest, wait for it to complete before proceeding.

Workflow

- [ ] Step 1: Ensure BackupRepo exists
- [ ] Step 2: Check BackupPolicy for the cluster
- [ ] Step 3: Create backup (on-demand or scheduled)
- [ ] Step 4: Verify backup

Step 1: Ensure BackupRepo Exists

A BackupRepo defines where backups are stored (S3, OSS, MinIO, GCS, etc.). At least one must be configured before creating backups.

kubectl get backuprepo

If no BackupRepo exists, see reference.md for setup instructions with various storage providers.

Step 2: Check BackupPolicy

Each cluster automatically gets a BackupPolicy when KubeBlocks creates it. Verify it exists:

kubectl get backuppolicy -n <ns>

The default naming convention is <cluster>-<component>-backup-policy. The BackupPolicy defines available backup methods and their configurations.

Step 3: Create a Backup

Option A: On-Demand Backup via OpsRequest

apiVersion: operations.kubeblocks.io/v1alpha1
kind: OpsRequest
metadata:
  name: <cluster>-backup-ops
  namespace: <ns>
spec:
  clusterName: <cluster>
  type: Backup
  backup:
    backupPolicyName: <cluster>-<component>-backup-policy
    backupMethod: <method>    # xtrabackup / volume-snapshot / pg-basebackup etc.
    deletionPolicy: Delete
    retentionPeriod: 7d

Before applying, validate with dry-run:

kubectl apply -f backup-ops.yaml --dry-run=server

If dry-run reports errors, fix the YAML before proceeding.

Apply it:

kubectl apply -f backup-ops.yaml
kubectl get ops <cluster>-backup-ops -n <ns> -w

Success condition: .status.phase = Succeed | Typical: varies | If stuck >30min: kubectl describe ops <cluster>-backup-ops -n <ns>

Option B: On-Demand Backup via Backup CR

apiVersion: dataprotection.kubeblocks.io/v1alpha1
kind: Backup
metadata:
  name: <backup-name>
  namespace: <ns>
spec:
  backupMethod: <method>
  backupPolicyName: <policy-name>
  deletionPolicy: Delete

Before applying, validate with dry-run:

kubectl apply -f backup.yaml --dry-run=server

If dry-run reports errors, fix the YAML before proceeding.

Apply it:

kubectl apply -f backup.yaml
kubectl get backup <backup-name> -n <ns> -w

Success condition: Full backup: .status.phase = Completed | Typical: varies | If stuck >30min: kubectl describe backup <backup-name> -n <ns> — Continuous backup: .status.phase = Running | Typical: 1min | If stuck >5min: kubectl describe backup <backup-name> -n <ns>

Option C: Scheduled Backup (Cluster CR)

Add a backup section to the Cluster CR spec:

spec:
  backup:
    enabled: true
    retentionPeriod: 30d
    method: xtrabackup
    cronExpression: "0 0 * * *"
    repoName: <repo-name>

Common cron expressions:

• "0 0 * * *" — daily at midnight
• "0 2 * * 0" — weekly on Sunday at 2 AM
• "0 */6 * * *" — every 6 hours

Option D: Continuous Backup for PITR

Continuous backups stream transaction logs (binlogs/WAL) to enable point-in-time recovery. Create a Backup CR with the continuous method:

apiVersion: dataprotection.kubeblocks.io/v1alpha1
kind: Backup
metadata:
  name: <cluster>-continuous
  namespace: <ns>
spec:
  backupMethod: archive-binlog    # MySQL; use wal-archive for PostgreSQL
  backupPolicyName: <cluster>-<component>-backup-policy
  deletionPolicy: Delete

For PITR to work, you need both a completed full backup and a running continuous backup.

Step 4: Verify Backup

kubectl get backup -n <ns>

Expected output shows Completed status:

NAME              POLICY                              METHOD        STATUS      AGE
my-backup         mycluster-mysql-backup-policy        xtrabackup   Completed   5m

Check backup details:

kubectl describe backup <backup-name> -n <ns>

Troubleshooting

Backup stuck in InProgress:

• Check BackupRepo connectivity: kubectl describe backuprepo
• Check backup pod logs: kubectl logs -n <ns> -l app.kubernetes.io/name=backup

BackupPolicy not found:

• Ensure the cluster is running: kubectl get cluster -n <ns>
• BackupPolicy is auto-created with the cluster; check addon installation

Volume-snapshot backup fails:

• Ensure a VolumeSnapshotClass exists: kubectl get volumesnapshotclass
• CSI driver must support volume snapshots

Additional Reference

For BackupRepo setup (S3, OSS, MinIO, GCS), continuous backup configuration, and advanced BackupPolicy customization, see reference.md.

For general agent safety conventions (dry-run, status confirmation, production protection), see safety-patterns.md.