NVMe stands for Non-Volatile Memory Express, and it refers to how software and storage communicate across PCIe and other protocols, including TCP. It's an open specification led by a non-profit organization and defines several forms of solid-state storage.
My laptop has an NVMe drive, as does my desktop. And they're fast. I love how quickly my computers boot and how quickly they're able to read and write data. There's no perceptible delay.
It also didn't take long for me to get curious about the technology driving this ultra-fast storage, so I did a little investigation. I learned that NVMe drives consume less power while delivering much faster access to data compared to even SSD drives over SATA. That was interesting, but I wanted to know more about my particular NVMe drives, and I wanted to know how they compared with other drives. Could I securely erase the drive? How could I check its integrity?
Those questions led me to an Internet search that yielded an open source project with a collection of tools to manage NVMe drives. It's called nvme-cli.
You can install
nvme-cli from your distribution's package manager. For instance, on Fedora, CentOS, or similar:
$ sudo dnf install nvme-cli
On Debian, Mint, Elementary, and similar:
$ sudo apt install nvme-cli
Exploring an NVMe drive
nvme-cli for my distribution, I wanted to explore my drive. There's no man page for
nvme-cli, but you can get lots of help by entering
$ nvme help nvme-1.14 usage: nvme <command> [<device>] [<args>] The '<device>' may be either an NVMe character device (ex: /dev/nvme0) or an nvme block device (ex: /dev/nvme0n1). The following are all implemented sub-commands: list List all NVMe devices and namespaces on machine list-subsys List nvme subsystems id-ctrl Send NVMe Identify Controller id-ns Send NVMe Identify Namespace, display structure id-ns-granularity Send NVMe Identify Namespace Granularity List, display structure list-ns Send NVMe Identify List, display structure list-ctrl Send NVMe Identify Controller List, display structure nvm-id-ctrl Send NVMe Identify Controller NVM Command Set, display structure primary-ctrl-caps Send NVMe Identify Primary Controller Capabilities [...]
List all NVMe drives
sudo nvme list command lists all NVMe devices and namespaces on your machine. I used it and found an NVMe drive at
/dev/nvme0n1. Here is the output:
$ sudo nvme list Node SN Model Namespace Usage Format FW Rev --------------------- -------------------- ---------------------------------------- --------- -------------------------- ---------------- -------- /dev/nvme0n1 S42GMY9M141281 SAMSUNG MZVLB256HAHQ-000L7 1 214.68 GB / 256.06 GB 512 B + 0 B 0L2QEXD7
I have a drive called
nvme0n1. It lists the serial number, brand, size, firmware revision, and so on.
You can get even more information about the drive and the features it supports by using the
$ sudo nvme id-ctrl /dev/nvme0n1 NVME Identify Controller: vid : 0x144d ssvid : 0x144d sn : S42GMY9M141281 mn : SAMSUNG MZVLB256HAHQ-000L7 fr : 0L2QEXD7 rab : 2 ieee : 002538 cmic : 0 mdts : 9 cntlid : 0x4 ver : 0x10200 rtd3r : 0x186a0 rtd3e : 0x7a1200 [...]
You can read about the overall health of a drive with the
$ sudo nvme smart-log /dev/nvme0n1 Smart Log for NVME device:nvme0n1 namespace-id:ffffffff critical_warning : 0 temperature : 21 C available_spare : 100% available_spare_threshold : 10% percentage_used : 2% endurance group critical warning summary: 0 data_units_read : 5,749,452 data_units_written : 10,602,948 host_read_commands : 77,809,121 host_write_commands : 153,405,213 controller_busy_time : 756 power_cycles : 1,719 power_on_hours : 1,311 unsafe_shutdowns : 129 media_errors : 0 num_err_log_entries : 1,243 Warning Temperature Time : 0 Critical Composite Temperature Time : 0 Temperature Sensor 1 : 21 C Temperature Sensor 2 : 22 C Thermal Management T1 Trans Count : 0 Thermal Management T2 Trans Count : 0 Thermal Management T1 Total Time : 0 Thermal Management T2 Total Time : 0
This provides you with the drive's current temperature, the hours of use it's had so far, how many times it was unsafely shut down, and so on.
Formatting an NVMe drive
You can format an NVMe drive with
nvme-cli, but beware: This erases all of the data on the drive! If there's important data on your drive, you must back it up before doing this, or else you will lose data. The subcommand is
$ sudo nvme format /dev/nvme0nX
(For safety, I've replaced the actual location of the drive with X to prevent copy-paste mishaps. Change the X to 1 or the appropriate location as listed in the results of
Securely erasing an NVMe drive
When you get ready to sell or dispose of your NVMe computer, you probably want to erase the drive securely. The same warnings apply here as with the format process: Back up important data first because this command erases it!
$ sudo nvme sanitize /dev/nvme0nX
nvme-cli command is released under a GPLv2 license. It's a robust command with lots of useful options, and it's a great way to take control of how you manage your data.