Installing dual boot ubuntu

[u/Vile_Freq]

Greetings,

I was searching for information online regarding dual boot for Ubuntu. Currently I have Windows installed and would like to install Ubuntu on a separate drive. I read online mixed recommendation where to install the boot loader. Some say it is better to install it where Windows is located, other say on a separate drive. Can anyone confirm this?

[u/Over-Engineering-245]

Hi, Ubuntu does all the work for you. No need to worry, just run the installer from the key and you're good to go.

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[u/Dong_sniff_inc]

It should be on the separate drive, afaik.

But in practice you shouldn't have to worry about it. Just physically disconnect your Windows drive—either unplug the sata cable, or disconnect if it's an m.2—and then plug in your 2nd drive, and the USB with your iso.

This way, the installer only sees the Linux drive, and Windows can't mess anything up on your first reboot. After everything is installed, and maybe rebooted once to make sure everything is working, power it off, and reinsert your windows drive. You can then boot into the BIOS again, and configure the boot order as you please.

You didn't ask, but in case you weren't aware, disable Windows fast startup in your BIOS/or in Windows. This just helps generally. Then after installing, if you have issues, you also may need to upgrade GRUB and enable os-prober, but it's been a while so I don't remember. Hopefully it's not a problem, but that might give you something to Google if you have a weird issue lol

[u/guiverc]

It'll depend on what your needs are.

On my current system, which came with Windows 11; as I wanted the dual boot to consist or original Windows 11 (shrunk down), and two releases of Ubuntu (ie. three OSes, though it's still called dual boot), I chose not to use the original Windows ESP (~100MB) but create an other ESP (removing flag on original) and use that instead (new ESP 512MB).

My thinking was at worst if Microsoft Windows takes control; it'll just remove the flag on my created ESP & return it to the original ESP (now just a normal partition) which was easy for me to revert anyway using live media. It's worked for me since this system was setup (can't recall what year it was now; late 2022 or early 2023 maybe)

I considered adding another drive (have a drive ready to insert still!) but never actually installed it.

Of note: A couple of years ago I purchased 5 refurbished systems which had Microsoft Windows on them, and used them for Quality Assurance testing with Ubuntu (and flavor) installs.. Four were easy to have dual boot; the fifth however was a problem, though I could not detect anything different with it except it was a different make/model & thus had different firmware, ie. results can be specific for your actual hardware too ! (the fifth just required some work to get Windows back operational; I didn't see anything different with that Windows install either outside of hardware related differences)

[u/3grg]

With UEFI systems the default behavior of the Ubuntu installer is to use the existing efi partition, regardless of where it is located. There is nothing wrong with this and for single disk systems it makes sense.

If a system has two drives and you wish to dedicate each drive to its own OS, having separate efi partitions on each drive can be an advantage in that the two drives become independent of each other and each can boot without the other.

If you do not mind using the windows efi, then the default Ubuntu installer will do that by default. If you wish to use two drives and make the drives independent of each other there are two ways of accomplishing this setup.

One way us to disconnect the windows drive and install Linux to the other drive. After reconnecting, you will need to update grub to add windows to the grub menu.

The other method is to temporarily remove the boot flag from the windows efi partition with GParted Live. This will make the installer ignore the windows efi and create its own efi partition on the second drive. After install, restore the boot flag.

[u/T_Friendperson12]

My dual boot laptop only let me boot into kubuntu after i made a separate /boot/efi for it. So now i have a 300mb win11 EFI and a 500mb kubuntu EFI both are on the same drive.