Create a directory at an abitrary place. Note the last directory name is important, call it mounted

% mkdir -p ~/Tmp/install/mounted

Place this following simple script at ~/Tmp/install called e.g createdisk.

# !/usr/bin/bash

if [[ -z "${1}" ]];then
    echo "give a name for the image to create"
    exit 1
fi

create() {
    local name="${1}"

    # create an empty file of 5G
    oblog "Create disk image: ${name}"
    truncate -s 5G "${name}"

    # format that image
    oblog "Format: ${name}"
    mkfs.ext4 -m 1 -v "${name}"

    # umount the previous mountpoint in case
    # of successively use of the script
    oblog "Umount mounted directory"
    umount -R mounted/

    # mount it
    oblog "Mount ${name}.img to mounted/"
    mount "${name}" mounted/

    # same as previous, in case of successive use
    # we erase the things done previously
    oblog "Delete mounted/{boot,home}"
    rm -rf mounted/boot
    rm -rf mounted/home
    oblog "Create directories mounted/{boot,home}"

    # finally create the boot, home directory
    mkdir mounted/{boot,home}

}

if (( EUID ));then
    oblog -f "you need to be root"
    exit 111
fi

create "${1}"

Move to the ~/Tmp/install directory, make the createdisk script executable and launch it.


This will create a virtual disk of 5G of size mounted at the directory ~/Tmp/install/mounted.

% cd ~/Tmp/install
% chmod +x createdisk
% sudo ./createdisk mysystem

mysystem is the name of the virtual disk.
Note: the script create a disk of 5G as size. You can increase/decrease it by changing the 5G value at the line

truncate -s 5G "${name}"

Now, you can install what you want on this directory.

Launch the obarun-install script and pick your /home/<user>/Tmp/install/mounted directory with the choose 1 on the obarun-install main menu.
Install the system as usual with obarun-install.(Note: you can create your own obarun-install-themes)
Obviously, you are not forced to use obarun-install to make this fresh installation. You can use what you want like pacstrap or directly by hand.

Install the obarun-mkiso.

% sudo pacman -S obarun-mkiso

Edit the /etc/obarun/mkiso.conf and set UPDATE="yes". At start, it will install the last commit of the obarun-mkiso project as obarun-install do when it ask you to udpate the script.

Launch the obarun-mkiso script

% sudo obarun-mkiso

Pick your /home/<user>/Tmp/install/mounted directory as directory to copy on ISO. Let the script doing the job. It will provide you an ISO from the fresh install made at /home/<user>/Tmp/install/mounted :).

Note, if you use multiple time the obarun-mkiso script do not forget to erase your previous build picking the number 13 at the obarun-mkiso main menu.

EDIT: maybe this explanation should appear somewhere at the obarun wiki.

Although it may be unofficial and outdated, look at the obarun zfs repo

https://repo.obarun.org/obzfs/ and https://repo.obarun.org/obzfs-testing

And welcome