Appendix A. Understanding the node_prep_inventory.yml file

A list of hyperconverged hosts that uses the back-end FQDN of the host, and the configuration details of those hosts. Configuration that is specific to a host is defined under that host’s back-end FQDN. Configuration that is common to all hosts is defined in the vars: section.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      [configuration specific to this host]
  vars:
    [configuration common to all hosts]

By default, Red Hat Virtualization Host enables multipath configuration, which provides unique multipath names and worldwide identifiers for all disks, even when disks do not have underlying multipath configuration. Include this section if you do not have multipath configuration so that the multipath device names are not used for listed devices. Disks that are not listed here are assumed to have multipath configuration available, and require the path format /dev/mapper/<WWID> instead of /dev/sdx when defined in subsequent sections of the inventory file.

On a server with four devices (sda, sdb, sdc and sdd), the following configuration blacklists only two devices. The path format /dev/mapper/<WWID> is expected for devices not in this list.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      blacklist_mpath_devices:
        - sdb
        - sdc

Include this section to define a list of devices to use deduplication and compression. These devices require the /dev/mapper/<name> path format when you define them as volume groups in gluster_infra_volume_groups. Each device listed must have the following information:

For example:

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_vdo:
      - { name: 'vdo_sdc', device: '/dev/sdc', logicalsize: '5000G',
        emulate512: 'off', slabsize: '32G', blockmapcachesize: '128M',
        writepolicy: 'auto' }
      - { name: 'vdo_sdd', device: '/dev/sdd', logicalsize: '500G',
        emulate512: 'off', slabsize: '2G', blockmapcachesize: '128M',
        writepolicy: 'auto' }

This section creates the volume groups that contain the logical volumes.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_volume_groups:
        - vgname: gluster_vg_sdb
          pvname: /dev/sdb
        - vgname: gluster_vg_sdc
          pvname: /dev/mapper/vdo_sdc

This section creates the logical volumes that form Gluster bricks.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_mount_devices:
        - path: /gluster_bricks/engine
          lvname: gluster_lv_engine
          vgname: gluster_vg_sdb
        - path: /gluster_bricks/data
          lvname: gluster_lv_data
          vgname: gluster_vg_sdc
        - path: /gluster_bricks/vmstore
          lvname: gluster_lv_vmstore
          vgname: gluster_vg_sdd

This section defines logical thin pools for use by thinly provisioned volumes. Thin pools are not suitable for the engine volume, but can be used for the vmstore and data volume bricks.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_thinpools:
        - {vgname: 'gluster_vg_sdc', thinpoolname: 'gluster_thinpool_sdc', thinpoolsize: '500G', poolmetadatasize: '16G'}
        - {vgname: 'gluster_vg_sdd', thinpoolname: 'gluster_thinpool_sdd', thinpoolsize: '500G', poolmetadatasize: '16G'}

This section defines cache logical volumes to improve performance for slow devices. A fast cache device is attached to a thin pool, and requires gluster_infra_thinpool to be defined.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_cache_vars:
        - vgname: gluster_vg_sdb
          cachedisk: /dev/sdb,/dev/sde
          cachelvname: cachelv_thinpool_sdb
          cachethinpoolname: gluster_thinpool_sdb
          cachelvsize: '250G'
          cachemode: writethrough

The thickly provisioned logical volumes that are used to create bricks. Bricks for the engine volume must be thickly provisioned.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_thick_lvs:
        - vgname: gluster_vg_sdb
          lvname: gluster_lv_engine
          size: 100G

The thinly provisioned logical volumes that are used to create bricks.

hc_nodes:
  hosts:
    new-host-backend-fqdn.example.com:
      gluster_infra_lv_logicalvols:
        - vgname: gluster_vg_sdc
          thinpool: gluster_thinpool_sdc
          lvname: gluster_lv_data
          lvsize: 200G
        - vgname: gluster_vg_sdd
          thinpool: gluster_thinpool_sdd
          lvname: gluster_lv_vmstore
          lvsize: 200G

Specifies the underlying hardware configuration of the disks. Set this to the value that matches your hardware: RAID6, RAID5, or JBOD.

hc_nodes:
  vars:
    gluster_infra_disktype: RAID6

Specifies the number of data disks in the RAID set. For a JBOD disk type, set this to 1.

hc_nodes:
  vars:
    gluster_infra_diskcount: 10

The stripe size of the RAID set in megabytes.

hc_nodes:
  vars:
    gluster_infra_stripe_unit_size: 256

Set this to true if you want to verify that your /var/log partition has sufficient free space during the deployment process. It is important to have sufficient space for logs, but it is not required to verify space requirements at deployment time if you plan to monitor space requirements carefully.

hc_nodes:
  vars:
    gluster_features_force_varlogsizecheck: false

Ensures that volumes can be accessed when SELinux is enabled. Set this to true if SELinux is enabled on this host.

hc_nodes:
  vars:
    gluster_set_selinux_labels: true

A list of ports to open between all nodes, in the format <port>/<protocol>.

hc_nodes:
  vars:
    gluster_infra_fw_ports:
       - 2049/tcp
       - 54321/tcp
       - 5900-6923/tcp
       - 16514/tcp
       - 5666/tcp
       - 16514/tcp

Ensures the ports listed in gluster_infra_fw_ports are open after nodes are rebooted. Set this to true for production use cases.

hc_nodes:
  vars:
  gluster_infra_fw_permanent: true

Enables the firewall. Set this to enabled for production use cases.

hc_nodes:
  vars:
    gluster_infra_fw_state: enabled

Specifies the firewall zone to which these gluster_infra_fw_\* parameters are applied.

hc_nodes:
  vars:
    gluster_infra_fw_zone: public

A list of services to allow through the firewall. Ensure glusterfs is defined here.

hc_nodes:
  vars:
  gluster_infra_fw_services:
     - glusterfs