Red Hat build of MicroShift

Basic LVMS configuration example

To customize storage operations, pass through your LVM configuration to MicroShift. With this flexibility, you can define custom volume groups, thin volume provisioning parameters, and reserved unallocated space by editing the LVMS configuration file.

You must restart MicroShift to deploy configuration changes after editing the file.

If you need to take volume snapshots, you must use thin provisioning in your lvmd.conf file. If you do not need to take volume snapshots, you can use thick volumes.

The following lvmd.yaml example file shows a basic LVMS configuration:

LVMS configuration example

socket-name:
device-classes:
  - name: "default"
    volume-group: "VGNAMEHERE"
    spare-gb: 0 
    default:

+ where:

socket-name: Specifies the UNIX domain socket endpoint of gRPC. Defaults to /run/lvmd/lvmd.socket. Takes a string value.
device-classes: Specifies a list of maps for the settings for each device-class.
device-classes.name: Specifies the name of the device-class. Takes a string value.
device-classes.volume-group: Specifies the group where the device-class creates the logical volumes. Takes a string value.
device-classes.spare-gb: Specifies the storage capacity in GB to be left unallocated in the volume group. Defaults to 0. Takes an unsigned 64-bit integer.
device-classes.default: Specifies that the device-class is used by default. Defaults to false. At least one value must be entered in the YAML file when this value is set to true. Takes a boolean value.

A race condition prevents LVMS from accurately tracking the allocated space and preserving the spare-gb for a device class when multiple PVCs are created simultaneously. Use separate volume groups and device classes to protect the storage of highly dynamic workloads from each other.