How to List Hardware Devices in Linux (lspci and lsusb)

The lspci command in Linux is the essential tool when you want to find out about drivers you're having trouble fixing (or simply need to see what's actually in your computer), along with lsusb for USB devices.

These commands provide you with a clear view of all the hardware installed in your Linux box, and together they give you information for virtually everything that is physically hooked up to it. lspci will show you the PCI bus and its associated devices. On the other hand, lsusb displays each USB controller plus all the devices which have been plugged into their ports.

These commands both originate from the same family of programs that pull data directly from the kernel. Both commands can be safely run by a standard user; they function in an identical manner among most distributions. Below, I'll walk you through twelve real-world examples of how I use these two commands in my daily administration activities. I've demonstrated each example using RHEL , Rocky Linux and Ubuntu .

Examples

The lspci command shows you all of the PCI devices that are visible to the kernel. It is the quickest method to get an overview of your system's internal hardware. Each line consists of the bus address for the PCI device, then the device class, followed by a brief vendor description for the pci device.

If you add -v on to lspci it will turn a single-line summary of a PCI device into a full report. This option provides additional information about the device, including the kernel module being used, IRQ (interrupt request), memory regions, and subsystem vendor. It is one of most commonly option I use when a device appears to be malfunctioning.

The -t option converts a flat list to a tree, allowing you to see what device resides behind each bridge. This can be helpful on servers with multiple PCI domains, or if you have bandwidth issues related to a specific slot.

While the vendor string may give you an idea of where to look, it is often that you will need the hexadecimal representation of the numeric vendor:device pair in order to search for a driver. The -nn option displays both the name and the numeric ID of the device on one line.

If a device appears in lspci yet isn't functioning, the first step I take is checking if the kernel even bound a driver to it. The -k flag will tell you this. It will give you information about the module or modules that are associated with the particular device, along with the driver.

Instead of having to scroll down the entire list, you can specify which device to focus on with lspci's -s flag, combined with -vv for maximum details.

Now let’s look at USB. The command lsusb will provide you with a listing of all devices enumerated by the kernel, each one listed on its own line. For each line there will be the bus number, the device number, the vendor:product identifier in hexadecimal format, and the name of the device as a string.

When you want to view a topology diagram showing how each device is related to the hubs they sit behind and their speeds, use lsusb with the -t option. This will allow you to quickly determine why a USB 3 device does not appear to be running at its intended speed; it may simply be plugged into a USB 2 port instead of a USB 3 port.

To dump the complete descriptor for every single device using lsusb, use the -v option. Due to the volume of information generated by this option, you usually pair it with -s to show information for only one device. Additionally, due to access restrictions to certain parts of the descriptors, you would need to run this command with elevated privileges.

If you want to narrow the amount of time spent viewing information from lsusb, use the -d option which allows you to filter based upon a given vendor:product ID.

If you are running many servers at one time, there can be many devices listed. There is no easier method of answering simple questions about your system such as "Do I have a network card installed?" or "Is my webcam working?" other than piping lspci or lsusb through grep to search for what you want quickly without having to look through every line.

You may also come across entries labeled "unknown device" followed by a vendor ID. This simply indicates that your local database does not currently contain information on this newer piece of hardware. By running update-pciids (which typically requires update-usbids to run as well), you can pull down a new list of IDs which will allow the proper name of the device to appear where previously it was unknown.