Data Disks

This section describes how to specify additional data disks for a linode instance. These disks can use devices sdb through sdh for a total of 7 disks.

Warning

There are a couple caveats with specifying disks for a linode instance:

  1. The total size of these disks + the OS Disk cannot exceed the linode instance plan size.
  2. Instance disk configuration is currently immutable via CAPL after the instance is booted.

Warning

Currently SDB is being used by a swap disk, replacing this disk with a data disk will slow down linode creation by up to 90 seconds. This will be resolved when the disk creation refactor is finished in PR #216

Specify a data disk

A LinodeMachine can be configured with additional data disks with the key being the device to be mounted as and including an optional label and size.

  • size Required field. resource.Quantity for the size if a disk. The sum of all data disks must not be more than allowed by the linode plan.
  • label Optional field. The label for the disk, defaults to the device name
  • diskID Optional field used by the controller to track disk IDs, this should not be set unless a disk is created outside CAPL
  • filesystem Optional field used to specify the type filesystem of disk to provision, the default is ext4 and valid options are any supported linode filesystem
---
apiVersion: infrastructure.cluster.x-k8s.io/v1alpha2
kind: LinodeMachineTemplate
metadata:
  name: ${CLUSTER}-control-plane
spec:
  template:
    spec:
      region: us-ord
      type: g6-standard-4
      dataDisks:
        sdc:
          label: etcd_disk
          size: 16Gi
        sdd:
          label: data_disk
          size: 10Gi

Use a data disk for an explicit etcd data disk

The following configuration can be used to configure a separate disk for etcd data on control plane nodes.

---
apiVersion: infrastructure.cluster.x-k8s.io/v1alpha2
kind: LinodeMachineTemplate
metadata:
  name: ${CLUSTER}-control-plane
spec:
  template:
    spec:
      region: us-ord
      type: g6-standard-4
      dataDisks:
        sdc:
          label: etcd_disk
          size: 16Gi

---
kind: KubeadmControlPlane
apiVersion: controlplane.cluster.x-k8s.io/v1beta1
metadata:
  name: "${CLUSTER_NAME}-control-plane"
spec:
    diskSetup:
      filesystems:
        - label: etcd_data
          filesystem: ext4
          device: /dev/sdc
    mounts:
      - - LABEL=etcd_data
        - /var/lib/etcd_data