Guide to the smartctl Utility in smartmontools for Linux

Introduction

smartctl is a command-line utility that is part of the smartmontools package, which provides tools for monitoring and managing the health of storage devices such as hard drives and SSDs. It allows users to check the status of Self-Monitoring, Analysis, and Reporting Technology (SMART) attributes in their drives, helping to detect early signs of drive failure. This guide will walk you through the installation, basic usage, and common commands of smartctl for Linux users.

What Is SMART?

SMART (Self-Monitoring, Analysis, and Reporting Technology) is a feature built into most modern hard drives and SSDs that monitors various attributes like temperature, read errors, and spin-up times. These attributes can give insight into the health and longevity of a drive, allowing users to predict potential failures and take action, such as backing up data or replacing the drive before a catastrophic failure occurs.

Installing smartmontools

Before you can use smartctl, you need to install the smartmontools package. Most Linux distributions have this package available in their repositories. Use the appropriate command for your distribution to install it:

• Debian/Ubuntu:
  sudo apt-get update
sudo apt-get install smartmontools

• CentOS/RHEL:
  sudo yum install smartmontools

• Fedora:
  sudo dnf install smartmontools

• Arch Linux:
  sudo pacman -S smartmontools


After installation, you can start using the smartctl command to check and manage your storage devices.

Checking Drive Health with smartctl

smartctl is a versatile tool that can be used for various tasks such as checking a drive’s health, running tests, and displaying detailed information about your drives. Below are some common smartctl commands and their descriptions.

1. Viewing Basic Information About a Drive

To see basic information about a storage device, such as its model number, serial number, and firmware version, use the following command:

Replace /dev/sdX with your actual device identifier (e.g., /dev/sda, /dev/sdb).

2. Checking the Overall Health of a Drive

To quickly check if a drive is healthy, use:

This command will display a simple “PASSED” or “FAILED” message, indicating whether the drive has detected any potential issues. It’s a quick way to determine if further testing is necessary.

3. Displaying All SMART Attributes

To get a detailed list of all SMART attributes that the drive monitors, use:

This command provides detailed statistics such as temperature, read error rates, and reallocated sectors count. Here are some key attributes to look for:

• Reallocated_Sector_Ct: Indicates the number of bad sectors that have been remapped.
• Current_Pending_Sector: Number of unstable sectors waiting to be remapped.
• Temperature_Celsius: Current temperature of the drive.

Interpreting these attributes can provide insights into the drive’s current condition.

4. Running a Short Self-Test

smartctl allows you to run self-tests directly on the drive to check for potential issues. A short test is a quick diagnostic that can be performed with the following command:

This test takes a few minutes and checks for basic read errors. After the test completes, you can view the results with:

5. Running a Long Self-Test

For a more thorough examination of the drive, you can run a long test:

The long test performs a more comprehensive analysis of the drive’s surface, but it can take several hours to complete, depending on the size and speed of the drive. Check the status of the ongoing test with:

6. Enabling or Disabling SMART

SMART is typically enabled by default on most drives, but in rare cases, it might be disabled. To enable SMART on a drive, run:

To disable it, use:

Enabling SMART is recommended as it allows you to take advantage of all the monitoring capabilities of smartctl.

Interpreting SMART Data

The SMART attributes reported by smartctl can seem cryptic at first. Here are a few key points to help you interpret the data:

• Raw_Read_Error_Rate: High values could indicate problems with the drive’s ability to read data accurately.
• Reallocated_Sector_Ct: A non-zero value could mean the drive is starting to develop bad sectors. If this number continues to increase, it could indicate a failing drive.
• Power_On_Hours: The total number of hours the drive has been powered on. This can give an idea of the drive’s age.
• Temperature_Celsius: High temperatures (above 60°C) can reduce the lifespan of a drive. It is best to keep it in the 30-40°C range.

Monitoring SMART Status Automatically

To keep track of your drive’s status over time, you can configure smartd, a background daemon included with smartmontools. It can automatically run tests and notify you via email if a drive starts showing signs of failure.

Edit the configuration file located at /etc/smartd.conf to specify which drives to monitor and how often tests should run. You can then enable and start the smartd service with:

Conclusion

smartctl is a powerful utility for monitoring and maintaining the health of your storage devices on Linux. By using the commands outlined in this guide, you can proactively check your drives for potential issues, perform diagnostic tests, and analyze detailed SMART data. Regular use of smartctl can help prevent data loss by identifying failing drives early, giving you time to back up important data and replace defective hardware.

With smartctl, you gain valuable insight into your drives’ health, ensuring the longevity and reliability of your storage infrastructure on Linux.