USB drive is labeled as "block device" and won't mount or open?

[p3rsonalv3nus]

Ubuntu Version

Ubuntu 24.04 LTS Flavors

Desktop Environment (if applicable)

MATE

Problem Description

hi! so i just updated from linux mint xfce to ubuntu MATE (noble numbat) a few days ago due to lag, and the good news is my computer is somehow doing better! i really love the UI and preinstalled programs.

however, the issue now is that my USB drive that has all my stuff on it is stored as a “block device”, and i dont know what that means and ive been looking at resources and still dont understand why my computer wont let me open it. ive made directories to mount it to:

sudo mount /dev/sdb /mnt

returns:

mount: /media/usb-drive: no medium found on /dev/sdb.
dmesg(1) may have more information after failed mount system call.

when i try to open it like a file from /dev with file explorer as the application, it says:
“could not display /dev/sdb”.
the location is not a folder"

lsblk will return:

loop0 7:0 0 519.5M 1 loop /snap/code-insiders/2545
loop1 7:1 0 406.1M 1 loop /snap/blender/7740
loop2 7:2 0 63.8M 1 loop /snap/core20/2922
loop3 7:3 0 74M 1 loop /snap/core22/2292
loop4 7:4 0 66.8M 1 loop /snap/core24/2124
loop5 7:5 0 4K 1 loop /snap/bare/5
loop6 7:6 0 74M 1 loop /snap/core22/2955
loop7 7:7 0 251.7M 1 loop /snap/firefox/7766
loop8 7:8 0 62.2M 1 loop /snap/ffmpeg-2204/150
loop9 7:9 0 260.8M 1 loop /snap/firefox/8863
loop10 7:10 0 18.5M 1 loop /snap/firmware-updater/210
loop11 7:11 0 16.5M 1 loop /snap/firmware-updater/226
loop12 7:12 0 242.6M 1 loop /snap/gaming-graphics-core24/13
loop13 7:13 0 531.4M 1 loop /snap/gnome-42-2204/247
loop14 7:14 0 531.5M 1 loop /snap/gnome-42-2204/263
loop15 7:15 0 614.5M 1 loop /snap/gnome-46-2404/164
loop16 7:16 0 91.7M 1 loop /snap/gtk-common-themes/1535
loop17 7:17 0 1.5G 1 loop /snap/kf5-core22/3
loop18 7:18 0 371.5M 1 loop /snap/krita/109
loop19 7:19 0 402M 1 loop /snap/mesa-2404/1839
loop20 7:20 0 292M 1 loop /snap/retroarch/3843
loop21 7:21 0 10.8M 1 loop /snap/snap-store/1270
loop22 7:22 0 48.1M 1 loop /snap/snapd/25935
loop23 7:23 0 576K 1 loop /snap/snapd-desktop-integration/343
loop24 7:24 0 50.3M 1 loop /snap/snapd/27738
loop25 7:25 0 828K 1 loop /snap/snapd-desktop-integration/391
loop26 7:26 0 291.2M 1 loop /snap/steam/271
loop27 7:27 0 519.5M 1 loop /snap/code-insiders/2547
loop28 7:28 0 405.6M 1 loop /snap/blender/7803
loop29 7:29 0 124K 1 loop /snap/usbutils-snap/2
loop30 7:30 0 4.1M 1 loop /snap/ipp-usb/399
sda 8:0 0 465.8G 0 disk
├─sda1 8:1 0 1G 0 part /boot/efi
└─sda2 8:2 0 464.7G 0 part /
sdb 8:16 1 0B 0 disk
sr0 11:0 1 1024M 0 rom

lsblk and lsusb will both tell me the USB is 0 bytes. im not sure what to do, i dont know if its corrupted, but i really hope it isnt. let me know if you need any more info! im not 100% sure what info is needed.

Relevant System Information

Disk /dev/sda: 465.76 GiB, 500107862016 bytes, 976773168 sectors
Disk model: TOSHIBA MQ01ABF0
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: F8520EC9-1E65-4C01-A9F4-B17AA2106888

Device Start End Sectors Size Type
/dev/sda1 2048 2203647 2201600 1G EFI System
/dev/sda2 2203648 976771071 974567424 464.7G Linux filesystem

HP notebook15

microSD usb2.0

Screenshots

[steelf]

/dev/sdb is a raw device, not a directory.
You cannot open it directly in a file manager or mount it until the system detects a valid media inside it. Usually, you mount partitions like /dev/sdb1, not the whole disk.

[p3rsonalv3nus]

ohhhh that makes more sense… /sdb is the only thing that pops up in /dev when i plug in my usb, i dont know why

[tea-for-one]

Attach your USB, open a terminal and enter

lsblk -e 7 -o name,size,pttype,type,fstype,fsuse%,fsavail,mountpoint

Please post the output within code tags </>

[p3rsonalv3nus]

sda 465.8G gpt disk
├─sda1 1G gpt part vfat 1% 1G /boot/efi
└─sda2 464.7G gpt part ext4 4% 415.1G /
sdb 0B disk
sr0 1024M rom

[tea-for-one]

Can you try again because your output is missing some info - specifically file system type etc.

PS I changed the tag to ubuntu-mate

[p3rsonalv3nus]

NAME SIZE PTTYPE TYPE FSTYPE FSUSE% FSAVAIL MOUNTPOIN
sda 465.8G gpt disk
├─sda1 1G gpt part vfat 1% 1G /boot/efi
└─sda2 464.7G gpt part ext4 4% 415.1G /
sdb 0B disk
sr0 1024M rom

this is all im getting

(thanks for fixing the tag, ive never used this forum before!)

[tea-for-one]

@p3rsonalv3nus

this is all im getting

It doesn’t look good so far.
Do you know what the file system should be?
Windows or Linux native file system?

Try a different USB port?

[steelf]

This is 100% a hardware issue, the USB adapter does not see the microSD card in its slot.
Are you sure it is inserted all the way?

[p3rsonalv3nus]

i made and formatted the USB to FAT32 (?) on my current computer (hp notebook 15) when it was running linux mint a few days ago, i dont know what native means but i did make my usb on linux, if thats what that means!!

[p3rsonalv3nus]

it seems okay with other usbs though!! heres a ventoy usb in the same usb port

[steelf]

FAT32 is completely fine and supported out of the box. The problem is not the filesystem or the switch from Linux Mint.

As mentioned above, your system currently detects the drive as “0 Bytes” (no medium found on /dev/sdb). When a drive shows 0 bytes, Linux cannot even reach the FAT32 filesystem because the reader does not see the physical memory card.

[p3rsonalv3nus]

aw, oh no that doesnt sound good, is there any way i can fix it?

[ericmarceau]

Is your “drive” a MicroSD inserted into a USB carrier stick?

If so, the connector strips on the MicroSD might need cleaning, and maybe blow into the carrier’s insertion slot to clear away any dust.

Dumb question: Did you actually insert the MicroSD in the carrier? or is the carrier stick empty?

If you still have issues, the MicroSD is a dud/fraud!

[p3rsonalv3nus]

oh NO i just realized theres an empty microSD slot on the back of the usb drive, my files are definitely gone thank you for your effort, everyone!!

[p3rsonalv3nus]

theres no possibility to recover files from your computer after switching the OS, is there?

[ericmarceau]

If you have overwritten the disk on the computer, and especially if you have reformatted to a different filesystem type (i.e. EXT4 insteat of NTFS) then there is no possibility of recovering the data.

IF you stayed with NTFS and installed the OS on top of that, there might be a remote chance of finding the data with disk recovery tools, but I am not an expert on those, for that scenario.

Others will need to speak to the complexity and issues.

[p3rsonalv3nus]

aw okay </3 thanks for your time!!

[steelf]

Time to check the /dev/vacuum_cleaner…