🟠 High   ⏱ 5–30 min  Last verified: 20 May 2026
Affected versions: SUSE Linux Enterprise Server 15

📖 ~1 min read

Table of contents
  1. Symptom & Impact
  2. Environment & Reproduction
  3. Root Cause Analysis
  4. Quick Triage
  5. Step-by-Step Diagnosis
  6. Solution – Primary Fix
  7. Solution – Alternative Approaches
  8. Verification & Acceptance Criteria
  9. Rollback Plan
  10. Prevention & Hardening
  11. Related Errors & Cross-Refs
  12. References & Further Reading

Symptom & Impact

Storage paths repeatedly transition between active and faulty, causing IO latency spikes.

Environment & Reproduction

Reported on SAN-attached SLES 15 hosts after fabric changes or HBA firmware updates.

Root Cause Analysis

Path checker timeouts and `polling_interval` do not match array recommendations.

Quick Triage

Inspect `multipath -ll` for failed and ghost paths.

Step-by-Step Diagnosis

Check `/etc/multipath.conf` and vendor-specific defaults documentation.

Illustrative mockup for sles-15 — multipath_path-flapping_terminal
Terminal diagnostics for Multipath devices flap between active and ghost — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Apply array-recommended defaults (path_checker, prio, polling_interval) and reload multipathd.

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Illustrative mockup for sles-15 — multipath_path-flapping_logs
Logs and evidence for Multipath devices flap between active and ghost — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Failover to a single fabric while replacing failing HBA or cable.

Verification & Acceptance Criteria

All paths show `active ready running` with stable IO and no `device-mapper: multipath` errors.

Rollback Plan

Restore previous multipath config from backup if performance regresses.

Prevention & Hardening

Validate fabric health quarterly and pin to certified HBA firmware.

Pairs with `path failed` and `path checker failed` log entries.

Related tutorial: View the step-by-step tutorial for sles-15.

View all sles-15 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

SUSE multipath and SAN vendor integration guides.

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