The arch-chroot command is a utility that is used to change the root directory of a running Linux system. It is typically used when installing a new operating system, or when performing system recovery or maintenance tasks.
The arch-chroot command works by changing the current root directory (/) to a different directory. This allows you to access and modify the files and directories within the new root directory as if they were on the root filesystem. For example, you might use arch-chroot to change the root directory to a bootable USB drive or live CD, and then perform system recovery or maintenance tasks from within that environment.
To use arch-chroot, you must first mount the desired root filesystem to a directory on the current system. For example, you might mount a bootable USB drive to the /mnt directory. Then, you can use the arch-chroot command to change the root directory to the mounted filesystem:
# sudo arch-chroot /mnt
After running this command, you will be able to access and modify the files and directories within the new root directory as if they were on the root filesystem. When you are finished, you can use the exit command to exit the chroot environment and return to the original root directory.
Note that arch-chroot is specific to the Arch Linux distribution, and may not be available on other Linux systems. Other distributions may provide similar functionality through different commands or tools.
arch-chroot Command Examples
1. Start an interactive shell (bash, by default) in a new root directory:
# arch-chroot {{path/to/new/root}}
2. Specify the user (other than the current user) to run the shell as:
# arch-chroot -u {{user}} {{path/to/new/root}}
3. Run a custom command (instead of the default bash) in the new root directory:
# arch-chroot {{path/to/new/root}} {{command}} {{command_arguments}}
4. Specify the shell, other than the default bash (in this case, the zsh package should have been installed in the target system):
# arch-chroot {{path/to/new/root}} {{zsh}}