Linux Software RAID Failure Alert - Troubleshooting Guide

KB 905655 - Linux Software RAID Failure Alert - Troubleshooting Guide

Purpose

This document provides a standardized approach for handling and troubleshooting the Linux Software RAID Failure alert, enabling L1 and L2 engineers to respond quickly, minimize risk, and maintain system stability.

Alert Name

Linux Software RAID Failure

Alert Description

This alert is triggered when a RAID disk failure is detected. It indicates that one or more RAID members have failed, placing the RAID array in a degraded state.

There is an immediate risk if another disk fails before the rebuild is completed.

Severity

P3 – Medium Impact

Possible Causes
  1. Disk hardware failure
  2. RAID member disk missing or disconnected
  3. I/O errors on disk
  4. RAID controller or configuration issues
  5. System-level disk detection issues

L1 Engineer Actions

Step 1 – Log the Alert

  1. Log in to the monitoring system
  2. Review:
    1. Alert summary
    2. Affected host/system

Step 2 – Create Ticket

  1. Create an internal ticket including:
    1. Alert name
    2. Hostname
    3. Timestamp
    4. Initial observations

Step 3 – Escalation (If required)

  1. Inform L2 team immediately
  2. Share alert details and observations

Step 4 – Documentation

  1. After confirmation with L2:
    1. Update Issue Master Sheet/ Issue Tracking Sheet

L2 Engineer Actions

Step 1 – Check RAID Status

cat /proc/mdstat
  1. Look for [UU] → healthy || [U_] or [_U] → degraded (one disk failed)
  2. Identify degraded RAID arrays
  3. Detailed info: sudo mdadm --detail /dev/md0
    1. State → clean, degraded, recovering
    2. Active Devices vs Failed Devices
  4. Note failed or missing disks

Step 2 – Identify Failed Disk

  1. Check which disk dropped:
    1. sudo mdadm --detail /dev/md0 | grep -i faulty
  2. Device name using lsblk  (e.g., /dev/sda, /dev/sdb)
    1. RAID group affected
  3. Cross-check logs:
    1. dmesg | grep -i error

Step 3: Mark Disk as Failed / Remove (if not already)

  1. sudo mdadm --manage /dev/md0 --fail /dev/sdX
  2. Then remove it: sudo mdadm --manage /dev/md0 --remove /dev/sdX

Step 4: Replace the Disk

  1. Physically replace the drive (or attach new one)
  2. Partition it (match existing layout)
  3. Copy partition table: sudo sfdisk -d /dev/sdY | sudo sfdisk /dev/sdX

Step 5: Add New Disk to Array & Monitor

  1. Add disk to array: sudo mdadm --manage /dev/md0 --add /dev/sdX
  2. Monitor the Rebuild: watch cat /proc/mdstat
    1. You will see: recovery = XX% complete

Step 6: Verify after rebuild

  1. Ensure:
    1. No failed devices
    2. State = clean
  2. sudo mdadm --detail /dev/md0

Step 7: Check Configuration Persistence

  1. Make sure RAID config is saved: sudo mdadm --detail --scan | sudo tee -a /etc/mdadm/mdadm.conf
  2. update initramfs: sudo update-initramfs -u

Step 8: Prevent Future Failures

  1. Enable SMART monitoring: sudo smartctl -a /dev/sdX
  2. Schedule regular RAID checks: echo check > /sys/block/md0/md/sync_action

Step 9 – Create OEM Support Ticket

  1. If issue is still persistent raise the concern with OEM
  2. Raise a ticket with hardware OEM
  3. Provide:
    1. RAID status output
    2. Server details
    3. Disk failure information

Resolution

The issue is considered resolved when:
  1. Failed disk is replaced
  2. RAID array is rebuilt successfully
  3. RAID status returns to healthy state
  4. No degraded arrays are present

Escalation

  1. L1 → L2: Immediate escalation after alert validation
  2. L2 → OEM/Vendor: For disk replacement and hardware support

    • Related Articles

    • KB 703359 - RAID Card Detection Validation Procedure

      This document outlines the standard technical steps to validate whether a RAID controller card is installed and detected correctly in a server system. These steps should be followed by field engineers and support teams whenever RAID detection issues ...

    • KB 905833 - Network Down Extern (P1 Critical Alert) - Troubleshooting Guide

      Purpose This document provides a standardized approach for handling and troubleshooting the Network Down - Extern alert, including L1 and L2 actions, escalation procedures, and resolution criteria for critical incidents. Alert Name Network Down - ...

    • 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 ...

    • KB 259003 - Set up RAID 0 using mdadm

      Steps to configure RAID 0 in Centos7. Code lsblk yum install -y mdadm mdadm --create --verbose /dev/md0 --level=0 --raid-devices=2 /dev/sdb /dev/sdc mkfs.ext4 /dev/md0 mkdir /mnt/raid0-drive mount /dev/md0 /mnt/raid0-drive df -h Code Summary LSBLK: - ...

    • KB 715314 - ZFS Pool Capacity Warning Alert - Troubleshooting Guide

      Purpose This document provides a standardized approach for handling and troubleshooting the ZFS Pool Capacity Warning alert, helping L1 and L2 engineers prevent storage exhaustion and maintain system stability. Alert Name ZFS Pool Capacity Warning ...

    • Recent Articles

    • KB-630208 | How to use Find and Locate to search for files in Linux

      Purpose To provide Linux administrators and Field Engineers with guidance on using the find and locate utilities to efficiently search for files and directories within a Linux filesystem based on criteria such as name, type, size, timestamps, ...

    • KB-630164 | How to use rsync to Synchronize Files

      Purpose To provide a clear and practical procedure for using the rsync utility to synchronize files and directories between local systems and remote hosts, including push and pull operations, while preserving file attributes and optimizing data ...

    • KB-630107 | How to create a Linux swap file

      Purpose To provide Field Engineers and Linux administrators with a standardized procedure for creating, configuring, and validating a Linux swap file. This procedure helps ensure sufficient virtual memory is available when physical RAM is exhausted ...

    • MSI All-in-One (AIO) PC – Physical Damage Policy for Warranty Claims

      MSI All-in-One (AIO) PC – Physical Damage Policy for Warranty Claims MSI's standard warranty does not cover physical or accidental damage to an All-in-One (AIO) PC. If the damage is determined to be caused by external factors rather than a ...

    • KB 134833 - Troubleshooting NVSM Alert NV-CPU-XX – Unrecoverable CPU Internal Error

      Purpose This document provides a general troubleshooting procedure for the NVIDIA System Management (NVSM) alert NV-CPU-XX, which indicates that a CPU has reported an internal error. The article outlines how to verify whether the alert represents an ...

    • Popular Articles

    • CP Plus Camera and NVR Configuration

      NVR Configuration The CP Plus Pro Series of NVRs have been meticulously designed for providing you with upgraded performance and higher recording quality in your IP video surveillance solution. The robust processor that has been inculcated in this ...

    • KB 775235 - Kerberos Authentication – Overview

      What is Kerberos? Kerberos is a secure authentication method used in our Active Directory (AD) environment (mbuzztech.com). It allows users to: Access multiple systems without re-entering passwords (Single Sign-On – SSO) Log in once Where We Use It ...

    • How to Remove and Reinstall NVIDIA Drivers on Ubuntu

      This article provides step by step guide to completely remove existing NVIDIA drivers and reinstall specific version of the NVIDIA driver on the Ubuntu system Prerequisites Administrative (sudo) access to the Ubuntu system. Internet access to ...

    • KB 692001 - Personal Computers and Servers - Classification and Point of Contact

      We can classify the computers that MBUZZ handles based on their form-factor as below: Tower Workstations, Desktops, Gaming PCs and SFF (Small form factor) PCs fall under this category. These are computers people would use on a desk and rarely move. ...

    • KB 298031 - M.2 SSD Tier List

      The sequential read and write speeds, which are usually the most advertised number, are not a proper benchmark of real-world performance or the quality of an SSD. This article categorizes and tiers SSDs based on factors like the type of NAND flash, ...