Arch Linux

860lacov

Member

Registered: 2020-05-02

Posts: 497

Do I understand dual boot install procedure?

Currently, I use Arch only, but I'll have to dual boot it witch Windows 10.
It's UEFI system.
I want to do this the simple way so clean install. W10 first, Arch second.

Am I correct that I should:

• Install Windows 10

• Disable fast boot and hibernation

• Install Arch the way Wiki says with EFI partition created by Windows mounted under /efi

  During the installation process:

• Install os-prober and packages I need

• Install GRUB and becouse os-prober is installed the Windows should be automatically detected

It seems that during system update Windows likes to overwrite the boot manager.
I'm not sure abut this but should GRUB recovery process look like this:?

• boot with Arch installation pendrive

• mount / as /mnt and efi partition as /mnt/efi

• chroot into /mnt

• install GRUB the same way like during Arch installation

• generate grub.cfg

Last edited by 860lacov (2021-02-12 07:59:33)

wadk

Member

Registered: 2021-02-11

Posts: 18

Re: Do I understand dual boot install procedure?

Heyo, went through this process myself recently. Personally, I wanted to use systemd-boot for cleaner look and faster boot. I followed the following post and finished with a functioning dual boot:
https://www.reddit.com/r/archlinux/comm … &context=3

Some comments I found through hard way:
- MAKE YOUR EFI LARGE ENOUGH, the degault efi was 100mb for me. You do this while installing windows, check link below. I did 512mb to be safe, you can get away with smaller one on systemd-boot.
https://www.ctrl.blog/entry/how-to-esp- … setup.html
- Loader-folder on /boot is your friend for editing setup for your linking in systemd-boot, link below
https://wiki.archlinux.org/index.php/sy … figuration
- It helped me to first focus on a windows 10 that boots from systemd-boot. Afterwards you can install pretty much whatever on the other partition(s). You can also edit lots of systemd-boot files when you see which files belong to windows: e.g. do cd /boot during Arch install and go through with ls what the folders have (or pacman -S tree to see the hierarchy tree)
- The guide linked is a good check list, but you should follow the Arch wiki too and a second guide just in case

Here are some notes for the steps in the guide:
- Check the Arch wiki for formatting and activating swap!
- You boot home folder to with "mount /dev/sda4 /mnt/home"
- For pacstrap -i /mnt, check from Arch wiki what you need instead. This is the step I would spend the most time on. Remember to have network manager, amd or intel -ucode, kernel, base, firmware. Have a minimal system with a network connection to boot into.
- For UUID, use "lsblk -f" for the step root=UUID=UUID_NUMBER_HERE, also Arch wiki adds rw at the end for some reason
e.g. options root=UUID=UUID_NUMBER_HERE rw
- You can do pretty much the whole install with arch-chroot /mnt, no need to restart as the guide says

Last edited by wadk (2021-02-13 08:02:12)

860lacov

Member

Registered: 2020-05-02

Posts: 497

Re: Do I understand dual boot install procedure?

I used grub to all my installs but maybe systemd is the way to go.

About the size. I'm aware of wimdows efi size.
For my Arch install i have 260MB as wiki says but...
I checked and my efi partition has less than 1MB space used.

I'll check your links.

loqs

Member

Registered: 2014-03-06

Posts: 19,022

Re: Do I understand dual boot install procedure?

I checked and my efi partition has less than 1MB space used.

As you are not using the ESP as /boot so it does not have to contain the kernel,  initrds and micrcode updates e.t.c.. As wadk is using systemd-boot those files have to go on the ESP.
Edit:
Does that 1MB include the files installed by Windows?  Would expect usage to be higher in that case.

Last edited by loqs (2021-02-12 15:25:45)

860lacov

Member

Registered: 2020-05-02

Posts: 497

Re: Do I understand dual boot install procedure?

I checked and my efi partition has less than 1MB space used.

As you are not using the ESP as /boot so it does not have to contain the kernel,  initrds and micrcode updates e.t.c.. As wadk is using systemd-boot those files have to go on the ESP.
Edit:
Does that 1MB include the files installed by Windows?  Would expect usage to be higher in that case.

No
No Windows fies yet. Its my pc with Linux only.
I checked wiki and it seems that I can't use systemd boot loader. I use btrfs file system.

I checked one more thing. I may use bitlocker.
Wiki says that I may need to unlock Windows partition with dislocker. When I don't need to do that?

loqs

Member

Registered: 2014-03-06

Posts: 19,022

Re: Do I understand dual boot install procedure?

I checked wiki and it seems that I can't use systemd boot loader. I use btrfs file system.

systemd-boot can only read the ESP so to use systemd-boot either the ESP has to be /boot or you have to use some other method so the kernel and initrd are copied onto the ESP.

Lone_Wolf

Administrator

From: Netherlands, Europe

Registered: 2005-10-04

Posts: 15,374

Re: Do I understand dual boot install procedure?

How come nobody linked to https://wiki.archlinux.org/index.php/Du … th_Windows ?

---

Disliking systemd intensely, but not satisfied with alternatives so focusing on taming systemd.

clean chroot building not flexible enough ?
Try clean chroot manager by graysky

wadk

Member

Registered: 2021-02-11

Posts: 18

Re: Do I understand dual boot install procedure?

I used grub to all my installs but maybe systemd is the way to go.

Found systemd-boot to be faster, but it is does not have as much features as grub. In your case, grub is probably your friend.

How come nobody linked to https://wiki.archlinux.org/index.php/Du … th_Windows ?

Personally, I found the wiki page to do a poor job of helping with a step to step install. It was especially hard to use the wiki, because it really just gives useful hints leaving user to read bookful of wikipages just to find the steps needed. It is impossible to give general instructions for every boot-loader and setup as the wiki page tries to accomplish. Therefore, only following the wiki you would have to spend couple of days to write instructions for yourself. The solution for me was to find someone else making a similar setup and following their footsteps. Step to step approach is especially important with dual boot setups, because of many reboots and everything having to work together.

Regardless, the arch wiki is amazing for finding solutions for isolated problems and commands. Also, for standard procedures like installs, updates, and DEs.

Last edited by wadk (2021-02-12 18:49:03)

finoderi

Member

Registered: 2020-06-12

Posts: 76

Re: Do I understand dual boot install procedure?

- MAKE YOUR EFI LARGE ENOUGH, the degault efi was 100mb for me. You do this while installing windows, check link below. I did 512mb to be safe, you can get away with smaller one on systemd-boot.
https://www.ctrl.blog/entry/how-to-esp- … setup.html

Yes, this is very important step and it's absolutely necessary if you are going to use systemd-boot as your bootloader. Because Windows ESP's 100 Mb won't be enough for kernel + initramdisk + fallback initramdisk, not to mention any other kernel in addition to the default one. As a result you won't be able to update your system. And the Wiki page doesn't mention it at all.

860lacov

Member

Registered: 2020-05-02

Posts: 497

Re: Do I understand dual boot install procedure?

Chamging Efi partition size it's not a problem.
It seems that if I will install arch the wiki way with grub then 100 MB will be sufficient.

If I understand correctly systemd boot will require more space.

I would like to ask about 3 more things.

1. Let's say that Windows will overwrite bootloader during system upgrade .
Can I just arch-chroot and install grub or another bootloader the same way as during Arch installation?

2. Can I just install Arch on different hard disk with second efi partition and chose disk to boot with bios? Is that possible?

3. I didn't find almost anything about dual boot with bit locker. Could you help mi with this?

loqs

Member

Registered: 2014-03-06

Posts: 19,022

Re: Do I understand dual boot install procedure?

1. Let's say that Windows will overwrite bootloader during system upgrade .
Can I just arch-chroot and install grub or another bootloader the same way as during Arch installation?

Yes,  although if Windows has only changed the boot order it would be enough to fix that.

2. Can I just install Arch on different hard disk with second efi partition and chose disk to boot with bios? Is that possible?

Yes,  however EFI views all ESP's as one logical ESP with a single boot order.

3. I didn't find almost anything about dual boot with bit locker. Could you help mi with this?

No knowledge,  I have never used it.

860lacov

Member

Registered: 2020-05-02

Posts: 497

Re: Do I understand dual boot install procedure?

Ok.
I'm not sure if I understand systemd-boot
Am I correct that
If I mount ESP to /EFI then the EFI partition doesn't have to be very large because kernel and ucode will be in /boot

But systemd-boot config files use relative paths so in example from wiki

title   Arch Linux
linux   /vmlinuz-linux
initrd  /amd-ucode.img
initrd  /initramfs-linux.img
options root="LABEL=arch_os" rw

But if I use /EFI then /amd-ucode.img will not be the correct path right?
Will I have to copy files form boot to /EFI?

p.s.1
I I would like to use full disk encryption (Arch) on btrfs then can I still use systemd-boot or I can use grub only?

p.s.2.
I'm pretty sure that I get everything wrong.

loqs

Member

Registered: 2014-03-06

Posts: 19,022

Re: Do I understand dual boot install procedure?

p.s.1
I I would like to use full disk encryption (Arch) on btrfs then can I still use systemd-boot or I can use grub only?

Encrypting_an_entire_system#Encrypted_boot_partition_(GRUB) is as in the link itself grub only,  full disk encryption excluding /boot can be done by systemd-boot.