CachyOS Installation Desktop/Laptop

Before you begin

Note

If you only get GRUB and Limine as boot manager options after pressing Launch Installer, then the system is booted in Legacy/BIOS mode.

Installing multiple desktop environments is not allowed during the installation process.

Secure Boot and CSM must be disabled in the BIOS/UEFI settings when installing in UEFI mode.

To set up Secure Boot after installation, refer to the Secure Boot section.

Legacy USB Support should be set to Auto.

Caution

The Install alongside and Replace partition options are not 100% reliable and can cause the installation to fail.

Manual partitioning is strongly preferred when installing CachyOS.

Tip

It is highly recommended to reboot into the ISO after a failed installation attempt.

Otherwise, continuous errors can happen during the installation process.

This happens because the installer doesn’t properly unmount partitions on a failed install.

Installation Methods

Manual Partitioning

Before proceeding with partitioning the disk for a UEFI installation.

Execute this command in the terminal

efibootmgr -v

If the output is EFI variables are not supported on this system., then the system is booted in Legacy/BIOS mode, and you need to ensure that UEFI mode is configured in the BIOS/UEFI settings. Refer to the Requisites section.

The partition table for each boot manager varies. Follow the instructions in Step 5 for the desired boot manager.

UEFI/GPT

1. Boot into the ISO and click on Launch Installer.

2. Set the preferred Language and Region/Timezone.

3. Configure the Keyboard Layout.

4. Select Manual partitioning.

5. Create a new partition with the following parameters depending on the boot manager of choice:

   Limine

   • Size: At least 4096 MiB

   • Filesystem: FAT32

   • Mount point: /boot

   • Flags: boot

   systemd-boot & rEFInd

   • Size: At least 2048 MiB

   • Filesystem: FAT32

   • Mount point: /boot

   • Flags: boot

   GRUB

   • Size: At least 512 MiB

   • Filesystem: FAT32

   • Mount point: /boot/efi

   • Flags: boot

6. Create another partition for root:

   • Size: At least 20000 MiB

   • Filesystem: Any, refer to Filesystem

   • Mount point: /

   • Flags:

7. Select the Desktop Environment of choice.

8. Choose which packages should be installed during the installation process.

9. Set up the login credentials.

10. Review the installation summary carefully. Proceed with the installation by clicking on Install Now if everything looks correct. Otherwise, go back and make any necessary changes.

MBR/BIOS

1. Boot into the ISO and click on Launch Installer.

2. Set the preferred Language and Region/Timezone.

3. Configure the Keyboard Layout.

4. Select Manual partitioning.

5. Create a new partition with the following parameters depending on the boot manager of choice:

   GRUB

   • Size: At least 20000 MiB

   • Filesystem: Any, refer to Filesystem

   • Mount point: /

   • Flags:

   Limine

   • Size: At least 4096 MiB

   • Filesystem: FAT32

   • Mount point: /boot

   • Flags: boot

   Another partition is needed for the root filesystem with the following parameters:

   • Size: At least 20000 MiB

   • Filesystem: Any, refer to Filesystem

   • Mount point: /

   • Flags:

6. Double check that Install boot loader on: is pointing to your boot drive, e.g., /dev/sda.

7. Select the Desktop Environment of choice.

8. Choose which packages should be installed during the installation process.

9. Set up the login credentials.

10. Review the installation summary carefully. Proceed with the installation by clicking on Install Now if everything looks correct. Otherwise, go back and make any necessary changes.

Dual Booting Windows and CachyOS

This guide assumes that Windows is already installed on the system and you decided to install CachyOS alongside it, sharing the same drive.

Caution

Dual booting Windows and Linux is not 100% reliable. Windows updates can break the bootloader by overwriting the EFI partition. In some cases, issues might never occur, but for some users it can be a recurring problem.

One way to avoid this issue is to install each operating system on a separate drive.

Caution

The EFI partition may need to be resized, depending on the recommended minimum size on the target boot manager. Refer to Manual Partitioning.

FAT filesystems cannot be resized in-place. To properly “resize” the FAT EFI partition, one must back up the existing EFI filesystem, use a tool such as gparted to resize the existing partition and reformat the new partition, then copy the previous filesystem structure back into the EFI partition.

Prerequisites

• Windows Fast Startup and Hibernation must be disabled.
  • Open Windows Powershell as administrator and execute the following command:

    powercfg /H off

    Reboot the system to ensure the changes take effect.
• Windows BitLocker must be disabled.
  • Checking if BitLocker is enabled:

    Open a Command Prompt as administrator and execute the following command

    manage-bde -status

  If Encryption Method shows as None, then BitLocker is disabled.
• Secure Boot must be disabled.
• A ≥30 GB empty partition.
  • Guide on how to shrink a Windows partition:
    • Press Win + R, type diskmgmt.msc, and press Enter to open Disk Management.
    • Identify your main Windows partition (usually C:) and right-click it.
    • Click on Shrink Volume..., specify at least 30720 MB (30 GiB), and click on Shrink.
• A bootable USB with CachyOS.
  • Refer to the Creating a Bootable CachyOS USB Drive section.

Limine

Limine should automatically detect the Windows EFI partition and add it to the boot menu. If Windows does not appear in the boot menu, run the following command:

sudo limine-scan

systemd-boot

We need to copy the Windows EFI binaries to the Linux EFI partition so that the boot manager can recognize them.

1. Locate the Windows EFI partition with lsblk.

   Execute this command in the terminal

   lsblk -o NAME,FSTYPE,SIZE,MOUNTPOINT

   Example output

               NAME        FSTYPE   SIZE MOUNTPOINT
   zram0               15.3G [SWAP]
   nvme0n1            476.9G
   ├─nvme0n1p1 vfat     100M
   ├─nvme0n1p2           16M
   ├─nvme0n1p3 ntfs   234.4G
   ├─nvme0n1p4 ntfs     830M
   ├─nvme0n1p5 vfat       2G /boot
   └─nvme0n1p6 btrfs  239.6G /var/tmp

   EFI partitions are almost always formatted as FAT32/vfat. Since nvme0n1p1 does not have a Linux mount point, we can assume that this partition is the Windows EFI partition.

2. Temporarily mount the Windows EFI partition.

   sudo mkdir /mnt/WinBoot
   sudo mount /dev/nvme0n1p1 /mnt/WinBoot # Replace `nvme0n1p1` with the name of the Windows EFI partition.

3. Copy the EFI binaries from the Windows EFI partition to the Linux EFI partition.

   sudo cp -r /mnt/WinBoot/EFI/Microsoft/ /boot/EFI

4. Unmount the previously-mounted partition. Windows should appear in the boot menu on the next startup.

   sudo umount /mnt/WinBoot
   sudo rm -r /mnt/WinBoot

GRUB (Only for older installations)

CachyOS enables os-prober by default.

GRUB uses os-prober to automatically detect the Windows EFI partition and add it to the boot menu.

1. Install os-prober.

   sudo pacman -S os-prober

2. Enable os-prober in the GRUB configuration file.

   Press CTRL+S to save and CTRL+Q to exit from Micro

   sudo micro /etc/default/grub
   # /etc/default/grub
   # Probing for other operating systems is disabled for security reasons. Read
   # documentation on GRUB_DISABLE_OS_PROBER, if still want to enable this
   # functionality install os-prober and uncomment to detect and include other
   # operating systems.
   GRUB_DISABLE_OS_PROBER=false

3. Update grub.cfg, now using os-prober.

   sudo grub-mkconfig -o /boot/grub/grub.cfg

   Windows should now be added to the boot menu.