sudo grub-install /dev/sdb 
sudo grub updateModel: ATA TS120GMTS820S (scsi)
Disk /dev/sda: 120GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 
Number  Start   End    Size    File system  Name                          Flags
 1      1049kB  106MB  105MB   fat32        EFI system partition          boot, esp
 2      106MB   123MB  16.8MB               Microsoft reserved partition  msftres
 3      123MB   119GB  119GB   ntfs         Basic data partition          msftdata
 4      119GB   120GB  567MB   ntfs                                       hidden, diag
Model: ATA TOSHIBA MQ02ABD1 (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags: 
Number  Start   End     Size    File system     Name                          Flags
 1      17.4kB  16.8MB  16.8MB                  Microsoft reserved partition  msftres
 2      16.8MB  766GB   766GB   ntfs            Basic data partition          msftdata
 3      766GB   903GB   136GB   ext4
 4      903GB   904GB   1024MB  linux-swap(v1)                                swap
 5      904GB   904GB   538MB   fat32           EFI System Partition          boot, esp