user@debian:~$ sudo mkdir /mnt/boot user@debian:~$ sudo mount /dev/sda1 /mnt/boot mount: /dev/sda1 is write-protected, mounting read-only mount: wrong fs type, bad option, bad superblock on /dev/sda1, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so. user@debian:~$ sudo fdisk -l Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors 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: 1884FC9F-764E-4E4C-9D5A-70D7A8428136 Device Start End Sectors Size Type /dev/sda1 2048 4095 2048 1M BIOS boot /dev/sda2 4096 1947267071 1947262976 928.5G Linux filesystem /dev/sda3 1947267072 1953523711 6256640 3G Linux swap Disk /dev/loop0: 878.2 MiB, 920829952 bytes, 1798496 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