set etcd size at 8 GB

controller/linodemachine_controller.go

@@ -49,6 +49,9 @@ import (
 	"github.com/linode/cluster-api-provider-linode/cloud/services"
 )
 
+// default etcd Disk size in MB
+const defaultEtcdDiskSize = 8192
+
 var skippedMachinePhases = map[string]bool{
 	string(clusterv1.MachinePhasePending): true,
 	string(clusterv1.MachinePhaseFailed):  true,
@@ -403,16 +406,15 @@ func (r *LinodeMachineReconciler) configureDisks(
 	}
 	instanceConfig := configs[0]
 
-	// carve out half the root disk space to be used for the etcd disk
+	// carve out space for the etcd disk
 	rootDiskID := instanceConfig.Devices.SDA.DiskID
 	rootDisk, err := machineScope.LinodeClient.GetInstanceDisk(ctx, linodeInstanceID, rootDiskID)
 	if err != nil {
 		logger.Error(err, "Failed to get root disk for instance")
 
 		return err
 	}
-	//nolint:gomnd // cutting disk in half
-	diskSize := rootDisk.Size / 2
+	diskSize := rootDisk.Size - defaultEtcdDiskSize
 	if err = machineScope.LinodeClient.ResizeInstanceDisk(ctx, linodeInstanceID, rootDiskID, diskSize); err != nil {
 		logger.Error(err, "Failed to resize root disk")
 
@@ -425,7 +427,7 @@ func (r *LinodeMachineReconciler) configureDisks(
 		linodeInstanceID,
 		linodego.InstanceDiskCreateOptions{
 			Label:      "etcd-data",
-			Size:       diskSize,
+			Size:       defaultEtcdDiskSize,
 			Filesystem: string(linodego.FilesystemExt4),
 		},
 	)

docs/src/topics/etcd.md

@@ -5,5 +5,5 @@ This guide covers etcd configuration for the control plane of provisioned CAPL c
 ## Default configuration
 
 By default, etcd is configured to be on a separate device from the root filesystem on
-control plane nodes. The etcd disk is automatically sized to take up half of the
-storage on the Linode instance.
+control plane nodes. The etcd disk is automatically sized at 8 GB per recommendation
+from [the etcd documentation](https://etcd.io/docs/latest/dev-guide/limit/#storage-size-limit)