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CachyOS

CachyOS chroot Helper

cachy-chroot is a simple helper program to ease the process of chrooting into an existing CachyOS or Arch-based install. It lists all the partitions discovered on the machine and also supports listing BTRFS subvolumes. Last but not least, cachy-chroot also supports encrypted systems via LUKS. It will map each fstab entries to its designated crypttab entries and will gracefully close all LUKS volumes when exiting the chroot.

Usage

Section titled “Usage”
  1. Boot into a live ISO of CachyOS
  2. Open a terminal and enter the root user with sudo su
  3. Make sure you have the latest cachy-chroot installed by running:
    Terminal window
    pacman -Sy cachy-chroot
  4. Run cachy-chroot by typing:
    Terminal window
    cachy-chroot
    cachy-chroot will scan and list all available partitions.
    Terminal window
    Info: Found 3 block devices
    Info: Found partition: Partition: /dev/nvme0n1p1: FS: vfat UUID: EDA6-ED98
    Info: Found partition: Partition: /dev/nvme0n1p2: FS: btrfs UUID: b09a027e-a61d-424f-858f-2e02be61b342
    Info: Found partition: Partition: /dev/nvme0n1p4: FS: btrfs UUID: 66e84339-8c77-4131-afce-50ec2cf67a80
    ? Select the block device for the root partition (use arrow keys):  ›
    Partition: /dev/nvme0n1p1: FS: vfat UUID: EDA6-ED98
    ❯ Partition: /dev/nvme0n1p2: FS: btrfs UUID: b09a027e-a61d-424f-858f-2e02be61b342
  5. Select the partition that contains the root filesystem:
    Selecting root partition
    ✔ Select the block device for the root partition (use arrow keys):  · Partition: /dev/nvme0n1p2: FS: btrfs UUID: b09a027e-a61d-424f-858f-2e02be61b342
    Info: Selected BTRFS partition, mounting and listing subvolumes...
    Info: Mounting partition /dev/nvme0n1p2 at /tmp/cachyos-chroot-temp-mount-b09a027e-a61d-424f-858f-2e02be61b342-hwAeIm with options: []
    Info: Unmounting partition at /tmp/cachyos-chroot-temp-mount-b09a027e-a61d-424f-858f-2e02be61b342-hwAeIm
    ? Do you want to use CachyOS BTRFS preset to auto mount root subvolume? (y/n) › # Enter yes if on CachyOS

    If using CachyOS with BTRFS, enter y to use the CachyOS BTRFS preset. This will automatically mount the root subvolume and other important subvolumes such as /home, /var, /tmp and /srv. If you’re using a custom BTRFS layout or non-CachyOS system, enter n to manually select subvolumes.
  6. cachy-chroot will attempt to automatically mount all the partitions and subvolumes listed under /etc/fstab of the root device. If any partitions fail to mount, you will be notified and given the option to mount them manually if needed. You can choose no to skip mounting additional partitions.
  7. You are now in the chroot environment.
    Terminal window
    [root@CachyOS /]#
    You can now run commands as if you were booted into the installed system. For example, you can update the system with:
    Updating system in chroot
    pacman -Syu
    or perform other maintenance tasks as needed.
  8. When finished, exit the chroot environment by passing exit to the prompt or pressing CTRL+D on the keyboard.
    Exiting chroot
    exit
  9. After exiting, cachy-chroot will automatically clean up mounted partitions and close any LUKS containers. You’ll return to the live environment shell.

Troubleshooting

Section titled “Troubleshooting”
  • No partitions found: Ensure that the disk containing your installation is connected and recognized by the live system. You can check with lsblk or fdisk -l.
  • Automount fails for some partitions: You can try mounting them manually from within the chroot environment. cachy-chroot will ignore failures and continue.

FAQ

Section titled “FAQ”
  • Q: What is the use for mounting additional partitions?
    • A: There are several use cases for manually mounting additional partitions, including:
      • Broken or missing fstab file: You can manually mount necessary partitions (such as /boot or /home) to perform repairs or data recovery.
      • Updated partition UUIDs: If your system is not booting because you changed the UUID of a prtition, you can use cachy-chroot to mount the partitions and then update the fstab accordingly.

Learn More

Section titled “Learn More”