PVC resize validation should respect `enableVolumeExpansion` setting

[chinaboard]

Proposal

Problem Summary

When using PXCs with fixed-size PVCs that are backed by dedicated disks of different sizes, the operator throws a blocking error even when volume expansion is disabled (enableVolumeExpansion: false).

Current Behavior

The operator performs size validation (requested < actual) before checking the enableVolumeExpansion setting, causing blocking errors when:

1. Volume expansion is disabled
2. Users have heterogeneous disk sizes backing their PVCs
3. The requested size must be set to the smallest common denominator

Expected Behavior

When enableVolumeExpansion: false, the operator should:

1. Accept the current configuration without blocking errors
2. Emit a warning event when requested size < actual size (instead of failing)
3. Only block operations when volume expansion is actually enabled

Use-Case

In environments where:

• PVCs are backed by dedicated physical disks
• Disk sizes vary across nodes (e.g., 100GB, 120GB, 150GB disks)
• The PVC request must be set to the smallest size (100GB) to work across all nodes
• Volume expansion is intentionally disabled

Is this a feature you are interested in implementing yourself?

No

Anything else?

No response

[chinaboard]

Relevant code blocks:

	if requested.Cmp(actual) < 0 {
		if err := r.revertVolumeTemplate(ctx, cr, configured); err != nil {
			return errors.Wrapf(err, "revert volume template in pxc/%s", cr.Name)
		}
		return errors.Errorf("requested storage (%s) is less than actual storage (%s)", requested.String(), actual.String())
	}

[hors]

hi @chinaboard Thank you for the report. I have created JIRA task to fix it https://perconadev.atlassian.net/browse/K8SPXC-1685 We will fix it in v1.20.0