zram Ansible playbook

zram.yml

---
- name: Manual ZRAM Setup
  hosts: your_servers
  become: yes
  tasks:
    - name: Install zram tools (Debian/Ubuntu example)
      ansible.builtin.apt:
        name: zram-tools
        state: present

    - name: Configure zram-generator
      ansible.builtin.copy:
        content: |
          [zram0]
          zram-fraction = 0.5
          max-zram-size = 1024 # Example: 1GB
        dest: /etc/systemd/zram-generator.conf
      notify: Restart zram service

    - name: Configure sysctl for memory management
      ansible.builtin.copy:
        content: |
          vm.swappiness=100
          vm.vfs_cache_pressure=500
          vm.oom_kill_allocating_task=1
        dest: /etc/sysctl.d/99-zram-memory.conf
      notify: Apply sysctl settings

    - name: Ensure zram service is running and enabled (if applicable)
      ansible.builtin.systemd:
        name: systemd-zram-setup.service
        state: started
        enabled: yes
      ignore_errors: yes # May not exist on all systems

  handlers:
    - name: Restart zram service
      ansible.builtin.systemd:
        name: systemd-zram-setup.service
        state

zram_v2.yml

---
# source: https://git.slub-dresden.de/digital-preservation/ansible_lza_install_common/-/blob/e05d20c9e7cea515d3bc2b3016e6c16829bb5a97/tasks/configure_swap.yml
- name: configure zram based swap (Debian)
  when: ansible_os_family == "Debian"
  block:
    - name: install zram
      ansible.builtin.package:
        name: "zram-tools"
        state: latest
    - name: configure zram based swap (Ubuntu)
      ansible.builtin.package:
        name: [ "linux-image-generic" ]
        state: latest
      when: ansible_distribution == "Ubuntu"
      notify: reboot
    - name: >
        Reboot instantly if linux-modules-extra-*-generic were newly installed.
        Otherwise, Ubuntu cannot load the zram.ko kernel module.
      ansible.builtin.meta: flush_handlers
    - name: configure zram
      ansible.builtin.blockinfile:
        path: "/etc/default/zramswap"
        block: |
          ALGO=lz4
          PERCENT=50
      notify: restart zramswap

# RHEL part is based on https://www.techrepublic.com/article/how-to-enable-zram-rocky-linux/
# More docu on zram at https://www.kernel.org/doc/html/latest/admin-guide/blockdev/zram.html
- name: configure zram based swap (RedHat)
  when: ansible_os_family == "RedHat"
  block:
    - name: disable swapping first, otherwise zram will not work
      ansible.builtin.command: "swapoff -a"
      changed_when: false
    - name: switch off swap (no result for running server, reboot persistent)
      ansible.posix.mount:
        path: "none"
        fstype: "swap"
        state: "absent"

    - name: load zram Kernel module
      ansible.builtin.lineinfile:
        path: "/etc/modules-load.d/zram.conf"
        create: true
        line: "zram"
        mode: "0644"
    # Use `zramctl -f` to show available zram devices.
    - name: configure zram Kernel module. This will create a zram device.
      ansible.builtin.lineinfile:
        path: "/etc/modprobe.d/zram.conf"
        create: true
        line: "options zram num_devices=1"
        mode: "0644"
    - name: configure udev to initialise zram device on bootup
      ansible.builtin.lineinfile:
        path: "/etc/udev/rules.d/99-zram.rules"
        create: true
        line: "KERNEL==\"zram0\", ATTR{disksize}=\"{{ (ansible_facts.memtotal_mb / 2) | round | int }}M\",TAG+=\"systemd\""
        mode: "0644"
    - name: find out if zram Kernel module has been loaded already
      ansible.builtin.command: "lsmod"
      register: kernel_modules
      changed_when: false
    - name: load zram Kernel module
      ansible.builtin.command: "modprobe zram"
      when: "not 'zram' in kernel_modules.stdout"
      changed_when: false
    - name: find existing zram devices
      ansible.builtin.command: "zramctl --noheadings"
      register: "zram_devices"
      changed_when: false
    - name: setup zram device
      ansible.builtin.command: "zramctl -a lzo -s {{ (ansible_facts.memtotal_mb / 2) | round | int }}M /dev/zram0"
      changed_when: false
    - name: create SystemD unit directory
      ansible.builtin.file:
        path: "/usr/local/lib/systemd/system/"
        state: directory
        mode: "0755"
    - name: create Systemd unit for zram
      ansible.builtin.copy:
        src: "usr/local/lib/systemd/system/zramswap.service"
        dest: "/usr/local/lib/systemd/system/zramswap.service"
        mode: "0644"
      notify: restart zramswap

- name: configure zram based swap (common)
  block:
    - name: start zram service
      ansible.builtin.systemd_service:
        name: "zramswap.service"
        daemon_reload: true
        state: started
        enabled: true