Install Linux Mint to 2nd hard drive with full disk encryption

[mikewinddale]

So I'm trying to do something I thought would be extremely simple, but it's turning out to be extremely difficult.

Basically, what I want to do is install Linux to a second disk without affecting the first disk at all. It turns out that that's paradoxically difficult. Somehow, it's easier to install Linux to the same disk as Windows than it is to install Linux to a blank disk.

My computer had one NVMe drive with Windows installed. I installed a second blank NVme drive, and my plan was to install Linux Mint to the second blank NVMe drive, with full disk encryption, with each drive having its own bootloader. So the Windows and Linux drives would be totally independent from one another.

But when I booted the Linux Mint Live USB, it only gave me two options:
(1) Install Linux Mint to the first drive, alongside Windows, or
(2) "Something else"

With #2, I had to manually create partitions, and I could only encrypt Home, not the full disk. Only #1 offered full disk encryption, but it would require installing Linux Mint to the first drive instead of to the blank second drive.

I did #2, and then I booted successfully into Linux. So it worked, but it isn't what I wanted.

Then, I booted back into the Linux Mint Live USB to see what options it would give me now that I had both Windows and Linux installed. Now, it said that it detected multiple operating systems, and the options were:
(1) Install Linux Mint alongside both Windows and Linux, as a 3rd OS
(2) Erase "the disk" (which disk? it didn't say) and install Linux Mint to "the disk" (which disk?)
(3) "Something else"

The strange thing with #2 was it didn't say which disk it would erase. My system had two disks, one with Windows and one with Linux, and yet the installer didn't even tell me which disk it had in mind. I pursued this option as far as I could go until I got to "Install now," at which point I stopped and backtracked. At no point did it ever give me the option of choosing which disk I wanted to erase and install Linux to.

So I'm very confused. I thought it would be very easy to install Linux Mint to a brand new, blank disk, without affecting Windows on another disk. And I thought I could choose full disk encryption if installing Linux Mint to a blank disk. And yet somehow, it turns out to be very difficult to select the blank disk.

So am I missing something? The only thing I can think of to try now, is to physically remove the first drive from the computer so that Linux only sees the second drive. Then, I can install Linux Mint to the second, blank drive and then I can physically reinstall the first drive (with Windows) again. But surely I shouldn't have to physically remove the first drive just to convince Linux Mint to install to the second drive, should I?

[catweazel]

Basically, what I want to do is install Linux to a second disk without affecting the first disk at all.

Remove the first NVMe.

[cliffcoggin]

When I had a second drive fitted for me I installed Mint onto it, albeit unencrypted, leaving Win7 on the first drive, and it was all fairly straightforward using the "something else" option of the installation. I don't recall the details now but the discs could be identified in the partitioning tool as sda for the first Windows drive and sdb for the second Linux drive. I believe that even if you choose to erase a disc you will be asked for confirmation and hence get a chance to go back if the wrong choice has been made.

[mikewinddale]

Basically, what I want to do is install Linux to a second disk without affecting the first disk at all.

Remove the first NVMe.

I thought of that, but why is that necessary? It seems like installing Linux to a blank, secondary drive ought to be easier than installing it to the same drive that already has Windows - not harder. Why is it so hard to install to a blank drive without physically removing all other drives?

[mikewinddale]

When I had a second drive fitted for me I installed Mint onto it, albeit unencrypted, leaving Win7 on the first drive, and it was all fairly straightforward using the "something else" option of the installation. I don't recall the details now but the discs could be identified in the partitioning tool as sda for the first Windows drive and sdb for the second Linux drive. I believe that even if you choose to erase a disc you will be asked for confirmation and hence get a chance to go back if the wrong choice has been made.

Indeed, I was able to go back, so nothing got erased. The problem is that "Something else" doesn't give you the option of full-disk encryption.

[pbear]

I thought of that, but why is that necessary?

Because the Ubuntu team which developed the installer didn't anticipate your scenario. Will take a major rewrite to fix (there are other issues besides this one) and not in prospect any time soon. Doesn't matter, really. It is what it is.

[mikewinddale]

Okay, I think I might have figured out how to install to a blank secondary disk without having to physically remove the first disk.

I physically removed my primary disk, began installing to the secondary disk, and I was asked to enter a password for my full-disk encryption. At the bottom of the screen, it said, "Install now."

I chose a password and clicked "Install now," expecting it to start immediately erasing and rewriting my disk. Instead, it asked me which disk I wanted to install to. From the drop-down, I was able to select the disk I wanted. (And Linux installed without a problem.)

So that makes me suspect that even if I hadn't removed the primary drive, I still would have gotten that same option to select a disk. Apparently, clicking "Install now" lets you choose which disk to install to, which is the option I had been searching for all along.

The reason I didn't see it before was that I thought "Install now" was the point of no return, so I hadn't ever clicked that button to see what came past it. I thought "Install now" meant "Start erasing and rewriting your disk now," whereas it turns out that it actually means, "Pick which disk to use."

Now I'm looking for illustrated guides to installing Linux to see if I can see whether this sequence of events was normal. Here, at figure 6, we see the screen where you are asked to choose a disk to install to. So that's the screen I wanted all along. I simply couldn't find it before because I was afraid to click a button labeled "Install now" when I hadn't yet picked a drive.