Cordon Pools

Overview

Pool Cordon allows you to temporarily prevent new replicas, snapshots, restores, or imports from being scheduled on a specific Replicated PV Mayastor pool. Use cordon during planned maintenance, hardware investigations, or controlled decommissioning. Existing data remains fully available and unaffected until explicitly migrated or removed.

Requirements

You can configure the maximum pool size using the maxExpansion field in the DiskPool CR.

• Replicated PV Mayastor deployment with a version that supports pool cordoning

• kubectl-mayastor or kubectl-openebs plugin installed and configured with appropriate administrative access

Cordon a Pool

When you cordon a pool, specify the resource types you want to block by including their flags. A flag’s presence sets that resource type to true (cordoned). If you omit a flag, that resource type remains uncordoned (false).

Cordon a pool to block new replicas and imports using kubectl-openebs. For Example: kubectl-openebs mayastor

Cordon a Pool to Block New Replicas and Imports

kubectl-openebs mayastor cordon pool <pool-name> --replicas

kubectl-openebs mayastor cordon pool <pool-name> --replicas --imports

Flags

• --replicas - Prevent new replicas from being created on the pool
• --snapshots - Prevent new snapshots from being scheduled
• --restores - Prevent new restore operations on the pool
• --imports - Prevent pool import operations.

Uncordon a Pool

When you uncordon a pool, you remove the scheduling restrictions and allow new resources to be created again. Use this when maintenance is complete or when you want the pool to resume normal operations.

Uncordon a Pool and Re-enable All Resource Scheduling

kubectl-openebs mayastor uncordon pool <pool-name> --replicas --imports

Flags

• The same flags apply as with cordon, letting you selectively enable scheduling for replicas, snapshots, restores, and imports.
• By default, running uncordon pool without flags will remove all existing cordons, restoring full scheduling for the pool.

Typical Use Cases

• Planned Maintenance: Isolate a pool before firmware upgrades or hardware replacement.
• Capacity Management: Prevent new replicas on a pool nearing its operational threshold.
• Controlled Decommissioning: Cordon, migrate replicas, and then retire the pool.

note

• Cordoning blocks new resources only. It does not move or delete existing data.
• Make sure enough other pools remain uncordoned to keep volumes healthy.
• Pools stay cordoned across restarts until you explicitly uncordon them.