How to tell which device the USB drive is assigned as?

Question

How can I tell which device the USB drive is assigned as?

Before inserting the USB drive:

$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
nvme0n1     259:0    0 238.5G  0 disk 
├─nvme0n1p5 259:3    0  15.9G  0 part [SWAP]
├─nvme0n1p1 259:1    0 222.6G  0 part /
└─nvme0n1p2 259:2    0     1K  0 part 

After:

$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda           8:0    1   1.9G  0 disk 
├─sda2        8:2    1   2.4M  0 part 
└─sda1        8:1    1   1.2G  0 part 
nvme0n1     259:0    0 238.5G  0 disk 
├─nvme0n1p5 259:3    0  15.9G  0 part [SWAP]
├─nvme0n1p1 259:1    0 222.6G  0 part /
└─nvme0n1p2 259:2    0     1K  0 part 

Is it /dev/sda??

Solution 1

Simply use lsblk output options to find it out:

lsblk -o NAME,TRAN

which produces:

sda                    sata
├─sda1
└─sda2           
sdb                    usb
└─sdb1                 
sr0                    sata

You can also use other options to get extra information (e.g: SIZE).
If you want a nice clean output use -S:

$ lsblk -So NAME,SIZE,TRAN

NAME   SIZE  TRAN
sda    400G  sata
sdb    16G   usb
sr0    1024M sata

Solution 2

How to find out which of your devices is a usb device

In short:

find /dev/disk -ls | grep usb

Or, on a specific device:

find /dev/disk -ls | grep usb | grep sda

If it has any output, sda is a usb device.

Long version

Information on your devices is to be found in the directory /dev/disk. Specifically the sub directories /dev/disk/by-id and /dev/disk/by-path give us information on wheter a device is a usb device or not. For example a name like:

usb-0930_USB_Flash_Memory_04506470B2D398CF-0:0

makes clear this is a usb drive.

If I run ls -l on the file, the output is:

lrwxrwxrwx 1 root root 9 apr 27 09:21 /dev/disk/by-id/usb-0930_USB_Flash_Memory_04506470B2D398CF-0:0 -> ../../sdb

which clearly shows this is sdb

Using find to filter out usb devices

The find ... -ls command, will subsequently give us the information we need.

You can easily find out which of the devices is a usb device by running the command:

find /dev/disk -ls | grep usb

To check if specifically sda is a usb device, run:

find /dev/disk -ls | grep usb | grep sda

If it has any output, it is a usb device.

It obviously looks like your usb device has two partitions:

sda           8:0    1   1.9G  0 disk 
├─sda2        8:2    1   2.4M  0 part 
└─sda1        8:1    1   1.2G  0 part