Ubuntu 22.04 LTS Multipath Device Names Change After Reboot

📖 ~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

LUN aliases differ after reboot, causing mount failures and application startup errors tied to device path assumptions in scripts and fstab entries.

Environment & Reproduction

Ubuntu 22.04 LTS with multipath-tools connected to SAN storage. Reproduce by rebooting when WWID-based aliases are not explicitly pinned in configuration.

Root Cause Analysis

Without stable alias definitions, multipath may assign names based on discovery order. Path timing differences across boots alter resulting device mapper names.

Quick Triage

List current multipath maps and compare against expected WWIDs before attempting remounts or service recovery.

Step-by-Step Diagnosis

Validate WWID discovery, blacklist rules, and alias sections. Confirm udev interactions and initramfs content include latest multipath settings.

Solution – Primary Fix

Define explicit multipath aliases per WWID, rebuild initramfs, restart multipathd, and update fstab to use persistent mapper paths.

Solution – Alternative Approaches

Use filesystem UUIDs in fstab, mount by labels, or rely on LVM metadata abstraction to reduce sensitivity to mapper alias names.

Verification & Acceptance Criteria

Aliases remain stable after two reboots, mounts succeed automatically, and application dependencies on block devices initialize without manual intervention.

Rollback Plan

Restore previous multipath.conf and initramfs, then remap devices using prior naming conventions if new aliases break dependent tooling.

Prevention & Hardening

Standardize WWID-to-alias mapping templates, validate multipath config in staging, and audit fstab entries for persistent identifiers only.

Related Errors & Cross-Refs

Commonly tied to duplicate WWIDs, stale udev rules, and SAN path failover behavior changes after firmware updates.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Consult multipath-tools docs, Ubuntu storage administration guides, and man pages for multipath(8), multipathd(8), and fstab(5).