Ansible Swapfile Save

What is ansible-swapfile?

It is an Ansible role to:

• Create a swap file
• Delete a swap file

Why would you want to use this role?

Having a swap file is useful. It will help protect you from the OOM killer going berserk and shutting down services, but it also gives the Linux kernel a place to dump less frequently accessed memory pages, so it can provide more memory to highly accessed memory pages. Basically it can improve overall system performance.

Supported platforms

• Ubuntu 16.04 LTS (Xenial)
• Debian 8 (Jessie)
• Debian 9 (Stretch)

Role variables

# Default to double your system's RAM capacity if you have 2GB or less.
swapfile_size: "{{ ((ansible_memtotal_mb | int * 2)
                    if (ansible_memtotal_mb | int <= 2048)
                    else '512') }}"

# Using fallocate is quite a bit faster than dd, so we'll default to using that.
# If your file system does not support fallocate, set this to False.
#
# If you're using one of the supported platforms you have it, so don't worry.
swapfile_fallocate: True

# Where should the swap file be created?
swapfile_path: "/swapfile-{{ swapfile_size }}"

# Settings to configure your swap file. Google them for more details.
swapfile_swappiness: 60
swapfile_vfs_cache_pressure: 100

# Default settings for configuring your swap file, you should not edit this
# directly. Instead use the variables above. This allows you to customize just
# 1 of them without having to bring along the entire dictionary.
swapfile_sysctl:
  "vm.swappiness": "{{ swapfile_swappiness }}"
  "vm.vfs_cache_pressure": "{{ swapfile_vfs_cache_pressure }}"

# When set to True, the swap file will be disabled and deleted.
swapfile_delete: False

Example usage

For the sake of this example let's assume you have a group called app and you have a typical site.yml file.

To use this role edit your site.yml file to look something like this:

---

- name: "Configure app server(s)"
  hosts: "app"
  become: True

  roles:
    - { role: "nickjj.swapfile", tags: "swapfile" }

Let's say you want to set a 4GB swap file and customize the swappiness, you can do this by opening or creating group_vars/app.yml which is located relative to your inventory directory and then making it look like this:

---

swapfile_size: 4096

swapfile_swappiness: 20

Now you would run ansible-playbook -i inventory/hosts site.yml -t swapfile.

Installation

$ ansible-galaxy install nickjj.swapfile

Ansible Galaxy

You can find it on the official Ansible Galaxy if you want to rate it.

License

MIT