ZFS Pool Error Alert - Troubleshooting Guide

KB 715260 - ZFS Pool Error Alert - Troubleshooting Guide

Purpose

This document provides a standardized approach for handling and troubleshooting the ZFS Pool Error alert, enabling L1 and L2 engineers to quickly identify disk-related issues, prevent data loss, and maintain storage reliability.

Alert Name

ZFS Pool Error

Alert Description

This alert is triggered when the ZFS error count is greater than 0, indicating underlying issues within the ZFS storage pool.

Errors reported by ZFS may include:
  1. Disk faults
  2. Checksum errors
  3. Data integrity issues
These errors often precede:
  1. Disk failure
  2. Pool degradation

Severity

P1- Critical Impact

Possible Causes

  1. Disk hardware failure
  2. Checksum/data corruption
  3. Faulty or degraded storage device
  4. I/O errors on disk
  5. Controller or connectivity issues

L1 Engineer Actions

Step 1 – Log the Alert

  1. Log in to the monitoring system
  2. Review alert summary and affected pool/system

Step 2 – Create Ticket

  1. Immediately create an internal ticket including:
    1. Alert name
    2. Hostname
    3. ZFS pool details
    4. Timestamp
    5. Initial observations

Step 3 – Escalation (If required)

  1. Inform L2 team immediately (P1 priority)
  2. Share alert details and observations

Step 4 – Documentation

  1. Update Issue Master Sheet with incident details
  2. Ensure proper tracking of the issue

L2 Engineer Actions

Step 1 – Check ZFS Pool Status

zpool status
  1. Review pool health
  2. Identify errors and affected devices

Step 2 – Check Checksum Errors

  1. Analyze output of zpool status & zpool list
  2. Look for:
    1. Checksum errors
    2. Read/write failures

Step 3 – Identify Faulty Disk

  1. Determine:
    1. Failed or degraded disk
    2. Affected pool and vdev

Step 4 – OEM Escalation

  1. Inform OEM/vendor with:
    1. ZFS status output
    2. Disk details
    3. System information

Step 5 – Disk Replacement & Resilver

  1. Replace faulty disk
  2. Monitor resilvering process:
zpool status -v
  1. Ensure pool returns to healthy state

Resolution

The issue is considered resolved when:
  1. ZFS pool status is healthy (ONLINE)
  2. No checksum or I/O errors are reported
  3. Resilvering completes successfully
  4. No further alerts are triggered

Escalation

  1. L1 → L2: Immediate escalation for P1 alerts
  2. L2 → OEM/Vendor: For disk replacement and hardware issues