Manual Partitioning in archinstall for dual boot Omarchy

[DoppioJP]

Omarchy, by design, uses entire disk. But for those willing to put some effort 👷‍♂️, dual boot is still possible with Omarchy. There are already some manuals to do that, but this one uses TUI from archinstall.

It is effectively an appendix for the official Manual installation - The Omarchy Manual, describing "Manual Partitioning" instead of using "Default partitioning layout" in the part of "Disk configuration"

Example names of disks are based on MacBookPro15,3 with T2 chip - 15-inch 2018 i9, as it is useful to keep macOS installed for some firmware.

Appendix for "Manual Partitioning"

1. Instead of using "best-effort default partition layout", choose "Manual Partitioning"
2. There you should see 2 disks (you will recognise which is which by the size):
   • the USB with ISO (i.e. /dev/sda)
   • APPLE SSD (i.e. /dev/nvme0n1)
3. Select the SSD and hit Enter. There you will see your existing partitions on that SSD disk
4. If you have prepared a dedicated partition, where you want your Omarchy to be installed, you should be able to find it. Select it and hit Enter. Choose "Delete partition". It will create the free space we need.
5. We will now manually create the same layout as the "best-effort default partition layout" does, but without touching partitions you want to keep.
   1. On that free space create 2 partitions:
      1. boot for Omarchy
         1. Size: 500MB (or more)
         2. Filesystem: fat32
         3. Mountpoint: /boot
      2. btrfs - that one will be encrypted with LUKS and will have the sub volumes
         1. Size: use the rest of the free space. Hit enter, so the default is used
         2. Filesystem: btrfs
         3. Now ready for sub volumes:

            1. Select that btrfs partition

            2. Set subvolumes > Add subvolume (we will add 4 of them):

               name	mountpoint
               @	/
               @home	/home
               @log	/var/log
               @pkg	/var/cache/pacman/pkg

            3. Confirm and exit

         4. Compression
            1. Select that btrfs again
            2. Mark/Unmark as compressed (after selecting it you should see compress=zstd under "Mount options" column)
   2. Confirm and exit
6. You should now see the info which shows you the btrfs partition to be created with 4 subvolumes and the table with those subvolumes
7. Encryption - follow as in the manual, but select your newly created btrfs partition

The rest as in the Manual installation - The Omarchy Manual

[Zeneixe]

@DoppioJP amazing tips here, these should be integrated in DHH's guide!

[marce-msv]

Totally agree with you!

[DoppioJP]

500MB boot partition for Omarchy was not enough when I was going through the installation for MacBookPro15,3 T2 - 15-inch 2018 i9. Some of the processes did not have enough room there, so I started again, but with 2GiB and it was enough for it.

• Omarchy on Macbook Intel (T2 chips) #773
• my journey of installing on MacBookPro15,3

If you come across some strange errors, where lack of space is mentioned, that might be the indication of the boot partition needed to be bigger.

[darshfi]

Is it necessary to have the btrfs file system, is it ok if I use ext4? Because right now I am trying to do the dual boot on windows but running into a problem when using curl -fsSL https://omarchy.org/install | bash, I have already installed arch like in the manual apart from the brtfs

[Dieterbe]

omarchi sets up btrfs snapshotting with a bootloader integration, and a UI to allow using prior snapshots and restoring them, so you need btrfs for those things.
if you can get it to boot and run with ext4, then your system should run fine, except for the snapshot related features

[alj-x64]

it says "Invalid configuration: EFI system partition (ESP) not found"

i already followed all steps here and on the Omarchy guide

[joshmccall221]

Mark/Unmark boot and esp on /boot partition

[Dieterbe]

This is very important: omarchi assumes you use 1 partition for both EFI and /boot. this may not be the default or the best practice. (i think it's common to have a dedicated /efi for all their operating systems, and a separate /boot).
At first i had them separate and got arch installed and booting just fine, but the omarchi script broke; i then re-did everything but with 1 partition for boot + efi, and then it worked.

so since i wanted to keep my normal arch install, and add a dualboot to omarchi, my original approach to keep a single efi partition for both, and a /boot for omarchi and a /boot for arch failed.
in the end i ended up with 2 efi partitions on one hard drive: one for arch and one for omarchi, i think this technically is against efi spec, but i think it works fine on many systems.
the alternative would have been 1 partition that is efi + boot for omarchi and efi for arch (and keep my separate boot for the normal arch), but i didn't trust omarchi enough to not mess up something for my arch install.

[ReiLoko4]

Is my thinking wrong or should we have already a partition install? its a must for a lot of people, as it intends to be easy...

[tuffs]

I second this and am following this thread for that very reason.

[C0DE33301]

Same here, ...

[nur-wahid123]

I have a problem after omarchy finished the installation, its finish and ask for reboot, but, after reboot i stuck on loading initramfs, i tried many ways possible, i cant make it runs

[tuffs]

Since this is a fresh install, I would ask if you have repeated the installation process again as it does wipe the disk anyhow, so you are not losing anything. With the speed of the installation process, this should be simple to do. You could troubleshoot it out but it would be far easier to just reinstall and see if that fixes things in my opinion.

[reztag]

video_20251008_050132.mp4

Trying this post about Manual Partition method for dual boot Omarchy solution. The single drive has Windows 11 and I wish to install Omarchy alongside it.

Im having this issue during archinstall where when I select my C drive (it has 71GB unallocated empty space) the screen goes blank.

I ensured im using GPT format bootable ISO

on skipping the "Disk Configuration" (to do it manually later) part archinstall doesnt proceed. I don't know what to select else

Edit: being more verbose

[reztag]

Hey, apologies for confusion. My intention was to clarify that while following the guide, ie, Manual Installation, I am not able to proceed further as the UI goes blank in selecting the drive. Unlike as mentioned in the post that it should give me further options, I am getting an empty screen with nothing on it

[ReiLoko4]

forgive my response then.

Thats really weird, do you have secure boot enabled or something?

[reztag]

• I have secured boot off
• I did pacman -Sy
• I have pre configured and mount my newly made partitions best I could

[Lixissimus]

When I follow this method and I install arch on a separate partition, but there is windows 11 on the same drive in its own partition, will it still be possible to boot into windows with the Limine bootloader?

[Prashanthveddula]

Yes you can - here is a YT tutorial for the same https://youtu.be/kE0foLfYkfk

[nightdevil00]

https://github.com/nightdevil00/DualBoot/blob/main/DUALBOOT-Windows_Arch_Limine.sh also helps

[AlvarodOrs]

Having a signatures issue when attempting, multiple people having the same issue.