stackhpc.beegfs

This Ansible role can be used to create and destroy a BeegFS cluster. In summary, BeegFS is a parallel file system that spreads user data across multiple servers. It is designed to be scalable both in terms of performance and capacity. Learn more about BeeFS here.

The role was last tested using Ansible version 2.5.0.

Example

Say we have an inventory that looks like this (inventory-beegfs):

[leader]
bgfs1 ansible_host=172.16.1.1 ansible_user=centos

[follower]
bgfs2 ansible_host=172.16.1.2 ansible_user=centos

[cluster:children]
leader
follower

[cluster_beegfs_mgmt:children]
leader

[cluster_beegfs_mds:children]
leader

[cluster_beegfs_oss:children]
leader
follower

[cluster_beegfs_client:children]
leader
follower

And a corresponding playbook as this (beegfs.yml):

---
- hosts:
  - cluster_beegfs_mgmt
  - cluster_beegfs_mds
  - cluster_beegfs_oss
  - cluster_beegfs_client 
  roles:
  - role: stackhpc.beegfs
    beegfs_enable:
      admon: false
      mgmt: "{{ inventory_hostname in groups['cluster_beegfs_mgmt'] }}"
      meta: "{{ inventory_hostname in groups['cluster_beegfs_mds'] }}"
      oss: "{{ inventory_hostname in groups['cluster_beegfs_oss'] }}"
      tuning: "{{ inventory_hostname in groups['cluster_beegfs_oss'] }}"
      client: "{{ inventory_hostname in groups['cluster_beegfs_client'] }}"
    beegfs_oss:
    - dev: "/dev/sdb"
      port: 8003
    - dev: "/dev/sdc"
      port: 8103
    - dev: "/dev/sdd"
      port: 8203
    beegfs_mgmt_host: "{{ groups['cluster_beegfs_mgmt'] | first }}"
    beegfs_client:
    - path: "/mnt/beegfs"
      port: 8004
    beegfs_fstype: "xfs"
    beegfs_force_format: false
    beegfs_interfaces: ["ib0"]
    beegfs_rdma: true
    beegfs_state: present
...

To create a cluster:

# ansible-playbook beegfs.yml -i inventory-beegfs -e beegfs_state=present

To destroy a cluster:

# ansible-playbook beegfs.yml -i inventory-beegfs -e beegfs_state=absent

Notes

Enabling various BeegFS services is as simple as configuring toggles under beegfs_enable to true or false where:

• mgmt: Management server - minimum one host
• mds: Metadata storage server nodes
• oss: Object storage server nodes
• client: Clients of the BeeGFS storage cluster
• admon: NOT IMPLEMENTED

This role is dependent upon each node's hostname resolving to the IP address used to reach the management host, as configured via beegfs_host_mgmt. In this case, bgsf1 and bgfs2 must resolve to 172.16.1.1 and 172.16.1.2 respectively. This may be done via DNS or /etc/hosts.

It is important to note that when provisioning the cluster, if the block devices specified already have a file system specified, or the disk is not empty, it is important to force format the disk. This can be set my setting beegfs_force_format to true. THIS WILL DELETE THE CONTENT OF THE DISK(S). Make sure you have made backups if you care about their content.

Partitions are supported but they must already have been created through another means. Additionally, you will also need override the variable beegfs_oss_tunable with a list of parent block devices since partitions do not live under /sys/block/. For example, to create partitions using an Ansible module called parted (works on Ansible version 2.5+), you can run the following playbook:

---
- hosts:
  - cluster_beegfs_oss
  vars:
    partitions:
    - dev: /dev/sdb
      start: 0%
      end: 50%
      number: 1
    - dev: /dev/sdb
      start: 50%
      end: 100%
      number: 2
  tasks:
  - name: Create partitions
    parted:
      label: gpt
      state: present
      part_type: primary
      device: "{{ item.dev }}"
      part_start: "{{ item.start }}"
      part_end: "{{ item.end }}"
      number: "{{ item.number }}"
    with_items: "{{ partitions }}"
    become: true
...

Tests

Some tests are provided in molecule folder. To run them locally you need:

• Vagrant
• VirtualBox
• Molecule
• python-vagrant

Once you have all the dependencies installed you can run the tests from the root folder of the role:

$> molecule lint
$> molecule test
$> molecule test -s vagrant-ubuntu-16.04
$> molecule test -s vagrant-ubuntu-18.04

• The default molecule scenario will test the role in a Centos7.5 machine.
• All the tests will deploy all the services in a single machine.
• yaml lint and ansible lint are tested
• idempotence is checked
• Once the execution finishes some testinfra are executed. All the scenarios use the same tests located in molecule/tests