Chapter 13. Configuring NFS storage

You can configure the overcloud to use shared NFS storage.

13.1. Supported configurations and limitations

Supported NFS storage

  • Red Hat recommends that you use a certified storage back end and driver. Red Hat does not recommend that you use NFS storage that comes from the generic NFS back end, because its capabilities are limited compared to a certified storage back end and driver. For example, the generic NFS back end does not support features such as volume encryption and volume multi-attach. For information about supported drivers, see the Red Hat Ecosystem Catalog.
  • For Block Storage (cinder) and Compute (nova) services, you must use NFS version 4.0 or later. Red Hat OpenStack Platform (RHOSP) does not support earlier versions of NFS.

Unsupported NFS configuration

  • RHOSP does not support the NetApp feature NAS secure, because it interferes with normal volume operations. Director disables the feature by default. Therefore, do not edit the following heat parameters that control whether an NFS back end or a NetApp NFS Block Storage back end supports NAS secure:

    • CinderNetappNasSecureFileOperations
    • CinderNetappNasSecureFilePermissions
    • CinderNasSecureFileOperations
    • CinderNasSecureFilePermissions

Limitations when using NFS shares

  • Instances that have a swap disk cannot be resized or rebuilt when the back end is an NFS share.

13.2. Configuring NFS storage

You can configure the overcloud to use shared NFS storage.

Procedure

  1. Create an environment file to configure your NFS storage, for example, nfs_storage.yaml.

  2. Add the following parameters to your new environment file to configure NFS storage: 

    parameter_defaults:
  CinderEnableIscsiBackend: false
  CinderEnableNfsBackend: true
  GlanceBackend: file
  CinderNfsServers: 192.0.2.230:/cinder
  GlanceNfsEnabled: true
  GlanceNfsShare: 192.0.2.230:/glance
    Note

    Do not configure the CinderNfsMountOptions and GlanceNfsOptions parameters, as their default values enable NFS mount options that are suitable for most Red Hat OpenStack Platform (RHOSP) environments. You can see the value of the GlanceNfsOptions parameter in the environments/storage/glance-nfs.yaml file. If you experience issues when you configure multiple services to share the same NFS server, contact Red Hat Support.

  3. Add your NFS storage environment file to the stack with your other environment files and deploy the overcloud: 

    (undercloud)$ openstack overcloud deploy --templates \
 -e [your environment files] \
 -e /home/stack/templates/nfs_storage.yaml

13.3. Configuring an external NFS share for conversion

When the Block Storage service (cinder) performs image format conversion on the overcloud Controller nodes, and the space is limited, conversion of large Image service (glance) images can cause the node root disk space to be completely used. You can use an external NFS share for the conversion to prevent the space on the node from being completely filled.

There are two director heat parameters that control the external NFS share configuration:

  • CinderImageConversionNfsShare
  • CinderImageConversionNfsOptions

Procedure

  1. Log in to the undercloud as the stack user and source the stackrc credentials file. 

    $ source ~/stackrc

  2. In a new or existing storage-related environment file, add information about the external NFS share. 

    parameter_defaults:
  CinderImageConversionNfsShare: 192.168.10.1:/convert
    Note

    The default value of the CinderImageConversionNfsOptions parameter, that controls the NFS mount options, is sufficient for most environments.

  3. Include the environment file that contains your new configuration in the openstack overcloud deploy command with any other environment files that are relevant to your environment. 

    $ openstack overcloud deploy \
--templates \
…
-e <existing_overcloud_environment_files> \
-e <new_environment_file> \
…
    • Replace <existing_overcloud_environment_files> with the list of environment files that are part of your existing deployment.
    • Replace <new_environment_file> with the new or edited environment file that contains your NFS share configuration.