Chapter 3. Preparing Storage for Red Hat Virtualization

Set up NFS shares on your file storage or remote server to serve as storage domains on Red Hat Enterprise Virtualization Host systems. After exporting the shares on the remote storage and configuring them in the Red Hat Virtualization Manager, the shares will be automatically imported on the Red Hat Virtualization hosts.

For information on setting up, configuring, mounting and exporting NFS, see Managing file systems for Red Hat Enterprise Linux 8.

Specific system user accounts and system user groups are required by Red Hat Virtualization so the Manager can store data in the storage domains represented by the exported directories. The following procedure sets the permissions for one directory. You must repeat the chown and chmod steps for all of the directories you intend to use as storage domains in Red Hat Virtualization.

Red Hat Virtualization supports iSCSI storage, which is a storage domain created from a volume group made up of LUNs. Volume groups and LUNs cannot be attached to more than one storage domain at a time.

For information on setting up and configuring iSCSI storage, see Configuring an iSCSI target in Managing storage devices for Red Hat Enterprise Linux 8.

# cat /etc/multipath/conf.d/host.conf
multipaths {
    multipath {
        wwid boot_LUN_wwid
        no_path_retry queue
    }

Red Hat Virtualization supports SAN storage by creating a storage domain from a volume group made of pre-existing LUNs. Neither volume groups nor LUNs can be attached to more than one storage domain at a time.

Red Hat Virtualization system administrators need a working knowledge of Storage Area Networks (SAN) concepts. SAN usually uses Fibre Channel Protocol (FCP) for traffic between hosts and shared external storage. For this reason, SAN may occasionally be referred to as FCP storage.

For information on setting up and configuring FCP or multipathing on Red Hat Enterprise Linux, see the Storage Administration Guide and DM Multipath Guide.

# cat /etc/multipath/conf.d/host.conf
multipaths {
    multipath {
        wwid boot_LUN_wwid
        no_path_retry queue
    }
  }

For information on setting up and configuring Red Hat Gluster Storage, see the Red Hat Gluster Storage Installation Guide.

For the Red Hat Gluster Storage versions that are supported with Red Hat Virtualization, see Red Hat Gluster Storage Version Compatibility and Support.

If your RHV environment is configured to use multipath connections with SANs, you can customize the multipath configuration settings to meet requirements specified by your storage vendor. These customizations can override both the default settings and settings that are specified in /etc/multipath.conf.

To override the multipath settings, do not customize /etc/multipath.conf. Because VDSM owns /etc/multipath.conf, installing or upgrading VDSM or Red Hat Virtualization can overwrite this file including any customizations it contains. This overwriting can cause severe storage failures.

Instead, you create a file in the /etc/multipath/conf.d directory that contains the settings you want to customize or override.

VDSM executes the files in /etc/multipath/conf.d in alphabetical order. So, to control the order of execution, you begin the filename with a number that makes it come last. For example, /etc/multipath/conf.d/90-myfile.conf.

To avoid causing severe storage failures, follow these guidelines:

Do not override the following settings:

Avoid overriding the following settings unless required by the storage system vendor: