How to use the command 'nvme' (with examples)

The NVMe command line interface (CLI) tool is a highly versatile user-space utility designed specifically for managing Non-Volatile Memory Express (NVMe) devices. This utility enables users to effectively monitor, manage, and troubleshoot NVMe storage components, ensuring optimal performance and reliability. The NVMe CLI provides detailed insights into NVMe devices, offering essential functionalities like listing all devices and retrieving device-specific information.

Use case 1: List all NVMe devices

Code:

sudo nvme list

Motivation:

In complex computing environments, it’s common to have multiple storage devices operating simultaneously. Whether you’re an IT professional managing a data center or an enthusiast setting up a high-performance personal system, quickly identifying all connected NVMe devices is beneficial. The command sudo nvme list is crucial for understanding the landscape of your NVMe devices. With this initial step, users can discover the available NVMe blocks, crucial for subsequent device management and operations such as configuration, monitoring, or diagnostics.

Explanation:

• sudo: This prefix is required to execute the command with superuser privileges, which are necessary for accessing hardware-level details in most operating systems.
• nvme: This specifies that the command should use the NVMe user-space utility.
• list: This argument directs the NVMe utility to enumerate all the NVMe devices connected to the system. It provides essential device information such as device paths, namespaces, disk sizes, and serial numbers.

Example Output:

When executed, the command produces a detailed list of all NVMe devices:

Node             SN                 Model                                  Namespace Usage                      Format           FW Rev
---------------- -------------------- ---------------------------------------- -------- -------------------------- ---------------- --------
/dev/nvme0n1     S3XXXXXXXXXXX       SAMSUNG MZVLB512HALU-000L2              1         256 GB / 256 GB            512   B + 0 B   4L1QEXA7
/dev/nvme1n1     PHXXXXXXXXXXX       HP SSD EX920 1TB                        1         1TB / 1TB                  512   B + 0 B   R0502D

Use case 2: Show device information

Code:

sudo nvme smart-log device

Motivation:

An NVMe device’s performance and reliability can degrade over time due to wear and other factors. Accessing real-time health data is essential for IT administrators and power users to track the health and performance of NVMe storage devices to avoid premature failures and optimize storage efficiency. The smart-log command provides valuable device-specific information such as temperature, power cycles, and error logs, empowering users with insights for proactive maintenance and troubleshooting.

Explanation:

• sudo: This ensures the command is executed with the requisite superuser privileges. Accessing device-specific diagnostic data typically requires elevated permissions.
• nvme: This invokes the NVMe CLI utility.
• smart-log: This command accesses the Self-Monitoring, Analysis, and Reporting Technology (SMART) log of an NVMe device, which contains critical health metrics.
• device: This is a placeholder where you input the specific NVMe device path obtained from the nvme list command, such as /dev/nvme0n1.

Example Output:

Upon successful execution, the command displays detailed health and statistics data for the specified device:

SMART/Health Information - NVMe Log:
critical_warning                    : 0
temperature                         : 40 C
available_spare                     : 100%
available_spare_threshold           : 10%
percentage_used                     : 0%
data_units_read                     : 2,345,678 [1200 LP]
data_units_written                  : 2,456,789 [1270 LP]
power_cycles                        : 15
power_on_hours                      : 34
unsafe_shutdowns                    : 1
media_errors                        : 0
num_err_log_entries                 : 0

Conclusion:

Utilizing the NVMe command line utility effectively allows users to manage their NVMe storage devices comprehensively. Recognizing and listing all NVMe devices sets the foundation for further storage management tasks. Subsequently, delving into specific device details through the SMART log offers insights into the health and performance of these devices. Understanding how to use these commands can enhance storage reliability, optimize performance, and avert potential problems in both personal and professional computing environments.