VMware vSAN: Troubleshooting [V8] — Lesson 3: Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior

Learning Objectives

• Identify the architecture and operational choices that shape Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior.
• Run normal and boundary tests and record the outcome in component-state timeline and repair decision record.
• Separate root cause from symptom when investigating premature disk removal increasing the number of inaccessible components.

Detailed Topics

• Disk groups
• Device failures
• Controller state
• Capacity pressure
• Component state
• Absent and degraded objects
• Policy compliance
• And resynchronization behavior
• Decision ownership, prerequisites, and acceptance evidence for Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior
• Relevant access, security, capacity, dependency, performance, recovery, and support considerations

Instructor Demonstration

The demonstration traces Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior from requirement through execution and review. Learners see where evidence should be collected, how component-state timeline and repair decision record supports validation, and which warning signs require investigation.

Hands-On Exercise

Build or execute Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior for a defined scenario. Introduce the condition “premature disk removal increasing the number of inaccessible components,” inspect the evidence, correct the cause without discarding the audit trail, and document the accepted state in component-state timeline and repair decision record.

1. Confirm scope, access, sample workloads, and acceptance criteria.
2. Perform the configuration or operation using a controlled sequence.
3. Inspect outputs and downstream effects rather than relying on task status alone.
4. Close with a support note, preventive action, and reproducible validation step.

Scenario Analysis

• Clarify the service trigger, affected components and roles, prerequisites, and acceptable result for Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior.
• Compare at least two implementation or correction choices and identify which evidence would distinguish them.
• Decide how component-state timeline and repair decision record should be reviewed, approved, retained, and handed to the next owner.

Troubleshooting Guidance

Diagnose Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior by checking effective state, ownership, dependencies, health, logs, and recent changes. Use component-state timeline and repair decision record to locate the earliest divergence. Treat “premature disk removal increasing the number of inaccessible components” as a hypothesis until the same test passes after correction and under a boundary condition.

Validation Checklist

• The requirement for Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior is linked to an owner and observable acceptance condition.
• Component-state timeline and repair decision record contains enough detail for another practitioner to repeat the check.
• Normal operation, one boundary condition, and the identified failure path have been tested.
• Access, security, downstream impact, rollback, monitoring, and support ownership are recorded.

Lesson Outcome

Learners can apply Disk groups, device failures, controller state, capacity pressure, component state, absent and degraded objects, policy compliance, and resynchronization behavior, explain the decisions made, and defend the result with component-state timeline and repair decision record.