xubuntu@xubuntu:~$ sudo su
root@xubuntu:/home/xubuntu# cd \
> /
root@xubuntu:/# sudo fdisk -l
Disk /dev/ram0: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram1: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram2: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram3: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram4: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram5: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram6: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram7: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram8: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram9: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram10: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram11: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram12: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram13: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram14: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/ram15: 64 MiB, 67108864 bytes, 131072 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


Disk /dev/loop0: 1.1 GiB, 1213882368 bytes, 2370864 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: 1.9 GiB, 1998585856 bytes, 3903488 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
Disklabel type: dos
Disk identifier: 0x58e117b2

Device     Boot Start     End Sectors  Size Id Type
/dev/sda1  *       32 3903487 3903456  1.9G  c W95 FAT32 (LBA)


Disk /dev/sdb: 465.8 GiB, 500107862016 bytes, 976773168 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: DD06AF41-B149-4097-8629-1E77CF380C6C

Device         Start       End   Sectors  Size Type
/dev/sdb1    1026048   1640447    614400  300M EFI System
/dev/sdb2    1640448   1902591    262144  128M Microsoft reserved
/dev/sdb3    1902592 802941046 801038455  382G Microsoft basic data
/dev/sdb4  802942976 869631722  66688747 31.8G Linux filesystem
/dev/sdb5  928651264 931966975   3315712  1.6G Linux swap
/dev/sdb6  931966976 932990975   1024000  500M Windows recovery environment
/dev/sdb7  933914624 934629375    714752  349M Windows recovery environment
/dev/sdb8  934629377 974675968  40046592 19.1G Windows recovery environment
/dev/sdb9  974675969 976773120   2097152    1G Windows recovery environment
/dev/sdb10 869632000 928651263  59019264 28.1G Linux filesystem

Partition 8 does not start on physical sector boundary.
Partition 9 does not start on physical sector boundary.
Partition table entries are not in disk order.


root@xubuntu:/# sudo mount -t ext4 /dev/sdb4 /mnt
mount: /dev/sdb4 is already mounted or /mnt busy
       /dev/sdb4 is already mounted on /mnt
root@xubuntu:/# sudo grub-install --root- directory=/mnt /dev/sdb
Installing for i386-pc platform.
grub-install: error: failed to get canonical path of `/cow'.
root@xubuntu:/# sudo grub-install --root- directory=/mnt /dev/sda
Installing for i386-pc platform.
grub-install: error: failed to get canonical path of `/cow'.
root@xubuntu:/# sudo grub-install --root- directory=/mnt /dev/sda4
Installing for i386-pc platform.
grub-install: error: failed to get canonical path of `/cow'.
root@xubuntu:/# sudo grub-install --root- directory=/mnt /dev/sdb4
Installing for i386-pc platform.
grub-install: error: failed to get canonical path of `/cow'.
root@xubuntu:/#