Hi I am trying to install Ubuntu on my new laptop, MSI GP62 6QF. It has Windows 10 installed on the 128 GB SSD. Now I want to install Ubuntu on the 1TB HDD. I booted into Ubuntu Live CD using a USB drive. I have choosen the following partitions for installation(I haven't made any change to SSD's partitions).
128 GB SSD Partitions:
/dev/sda
/dev/sd1 efi ------------ Windows Boot Manager
/dev/sd2
/dev/sd3 ntfs 126GB
/dev/sd4 ntfs 1GB
1TB HDD Partitions:
/dev/sdb
/dev/sdb1 ntfs 300GB
/dev/sdb2 ntfs 300GB
/dev/sdb4 swap 4096 MB
/dev/sdb5 ext4 / 300GB
/dev/sdb3 ntfs 17GB (system recovery)
/dev/sdb4 and /dev/sdb5 partitions were created by me.
What I am confused about is what option should I select in "Device for boot Loader installation"? /dev/sda or /dev/sdb
sda
is where the EFI partition resides. You should boot Ubuntu in UEFI mode.