[Bug]: PVC VolumeAttributesClass reconciliation issues redundant PATCH updates · Issue #11194 · cloudnative-pg/cloudnative-pg · GitHub
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[Bug]: PVC VolumeAttributesClass reconciliation issues redundant PATCH updates #11194

Closed
Defect
#11196
Closed
[Bug]: PVC VolumeAttributesClass reconciliation issues redundant PATCH updates#11194
Defect
#11196
Assignees
gbartolini
Labels
bug 🐛Something isn't working
Milestone
1.30.1

Description

@andrew-farries
andrew-farries
opened on Jul 14, 2026

Is there an existing issue already for this bug?

  • I have searched for an existing issue, and could not find anything. I believe this is a new bug.

I have read the troubleshooting guide

  • I have read the troubleshooting guide and I think this is a new bug.

I am running a supported version of CloudNativePG

  • I have read the troubleshooting guide and I think this is a new bug.

Contact Details

andrew.farries@xata.io

Version

1.30.0

What version of Kubernetes are you using?

1.31

What is your Kubernetes environment?

Cloud: Amazon EKS

How did you install the operator?

YAML manifest

What happened?

Reconciliation of Cluster resources that set volumeAttributesClassName in a pvcTemplate always issues a redundant, empty PATCH operation against each of the cluster's PVCs, even when the PVC already carries the expected value. This is caused by an incorrect comparison here:

cloudnative-pg/pkg/reconciler/persistentvolumeclaim/existing.go

Lines 111 to 113 in 1a79065

The guard in reconcileVolumeAttributeClass compares two *string pointers with ==, which tests pointer identity rather than value equality. Since the template's pointer and the PVC's pointer never share an allocation, the comparison only succeeds when both sides are nil — with a volumeAttributesClass configured, it fails on every reconciliation.

The impact is limited to wasted API-server traffic: because the assigned value is identical, the computed merge patch is empty ({}), so the PVC is not actually modified. The existing unit test doesn't catch this because it assigns the same pointer to both the PVC and the template.

Introduced in #7885.

Cluster resource



Relevant log output




Code of Conduct


    

  •  I agree to follow this project's Code of Conduct
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Activity
  1. andrew-farries
    assigned 
    gbartolini
    on Jul 14, 2026
  2. andrew-farries
    added 
    bug 🐛Something isn't working
     
    triagePending triage
     on Jul 14, 2026
  3. dosubot commented on Jul 14, 2026 
    @dosubot
    dosubotBot
    on Jul 14, 2026 – with DosuBot
    


    Hi @andrew-farries! I'm Dosu and I'm helping the CloudNativePG team.
    

    Your analysis is correct. The comparison at line 111 [1] checks pointer identity (== on two *string values) rather than dereferenced value equality, so it will always fall through to the PATCH path when volumeAttributesClassName is set — even when the values are already identical.
    

    As you noted, the existing unit test for the "does nothing if VolumeAttributesClassName is already the expected value" case [2] reuses the same string variable for both the PVC and the template, which means both pointers share an address and the == check happens to pass — masking the bug in tests.
    

    A fix would be to replace the pointer comparison with a value-aware comparison, e.g. using ptr.Equal:
    

    if ptr.Equal(expectedVolumeAttributesClassName, pvc.Spec.VolumeAttributesClassName) {
    return nil
}
    

    And the test should be updated to use independently allocated *string values (e.g. via ptr.To("value") for each side) to properly exercise the comparison.
    


    To reply, just mention @dosu.
    

    

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  4. gbartolini
    added this to the  1.30.1 milestone on Jul 15, 2026
  5. gbartolini
    added this to  CloudNativePG operator developmenton Jul 15, 2026
  6. gbartolini
    added the
    Defect
    issue type on Jul 15, 2026
  7. gbartolini
    removed 
    triagePending triage
     on Jul 15, 2026
  8. mnencia
    closed this as completedin #11196on Jul 17, 2026
  9. github-project-automation
    moved this to Done in  CloudNativePG operator developmenton Jul 17, 2026
  10. cnpg-bot
    added 3 commits that reference this issue on Jul 17, 2026
    fix(pvc): use `ptr.Equal` for `VolumeAttributesClass` equality check (#…
    abb18c6
    fix(pvc): use `ptr.Equal` for `VolumeAttributesClass` equality check (#…
    4926ad1
    fix(pvc): use `ptr.Equal` for `VolumeAttributesClass` equality check (#…
    7095c2e
  11. pull
    added a commit that references this issue on Jul 17, 2026
    fix(pvc): use `ptr.Equal` for `VolumeAttributesClass` equality check (c…
    1462ab1
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