sudo fdisk -l
Disk /dev/loop0: 1.65 GiB, 1773535232 bytes, 3463936 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop1: 522.8 MiB, 548192256 bytes, 1070688 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop2: 895.65 MiB, 939159552 bytes, 1834296 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop3: 4 KiB, 4096 bytes, 8 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop4: 73.89 MiB, 77479936 bytes, 151328 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop5: 11.13 MiB, 11673600 bytes, 22800 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop6: 258.04 MiB, 270569472 bytes, 528456 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop7: 516.01 MiB, 541073408 bytes, 1056784 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/sda: 238.47 GiB, 256060514304 bytes, 500118192 sectors
Disk model: SanDisk SD8TB8U2
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: A9B5D8F3-D27C-40AB-8AC7-77BB66187DA9

Device     Start       End   Sectors   Size Type
/dev/sda1   2048      4095      2048     1M BIOS boot
/dev/sda2   4096 500115455 500111360 238.5G Linux filesystem


Disk /dev/sdb: 250 GiB, 268435456000 bytes, 524288000 sectors
Disk model: UDisk           
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x0aef60de

Device     Boot Start       End   Sectors  Size Id Type
/dev/sdb1  *     2048 524287935 524285888  250G  c W95 FAT32 (LBA)


Disk /dev/loop8: 91.69 MiB, 96141312 bytes, 187776 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop9: 10.77 MiB, 11292672 bytes, 22056 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop10: 44.44 MiB, 46596096 bytes, 91008 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop11: 568 KiB, 581632 bytes, 1136 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop12: 112.45 MiB, 117911552 bytes, 230296 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/loop13: 210.41 MiB, 220631040 bytes, 430920 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
ubuntu@ubuntu:~$ sudo mount /dev/sda /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sda, missing codepage or helper program, or other error.
       dmesg(1) may have more information after failed mount system call.
ubuntu@ubuntu:~$ sudo mount /dev/sdan /mnt
mount: /mnt: special device /dev/sdan does not exist.
       dmesg(1) may have more information after failed mount system call.
ubuntu@ubuntu:~$ sudo mount /dev/sda1 /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sda1, missing codepage or helper program, or other error.
       dmesg(1) may have more information after failed mount system call.
ubuntu@ubuntu:~$ sudo mount /dev/sda /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sda, missing codepage or helper program, or other error.
       dmesg(1) may have more information after failed mount system call.
ubuntu@ubuntu:~$