Make the filesystem overhead configurable

This patch will allow the user to configure the filesystem overhead.
Currently it defaults to 10%. The overhead is mainly required for ext4
and the root partition.

Signed-off-by: Liran Rotenberg <[email protected]>

operator/config/manager/manager.yaml

@@ -64,6 +64,8 @@ spec:
           value: ${SNAPSHOT_STATUS_CHECK_RATE}
         - name: CDI_EXPORT_TOKEN_TTL
           value: ${CDI_EXPORT_TOKEN_TTL}
+        - name: FILESYSTEM_OVERHEAD
+          value: ${FILESYSTEM_OVERHEAD}
         - name: POPULATOR_CONTROLLER_IMAGE
           value: ${POPULATOR_CONTROLLER_IMAGE}
         - name: OVIRT_POPULATOR_IMAGE

operator/roles/forkliftcontroller/defaults/main.yml

@@ -34,6 +34,7 @@ controller_snapshot_status_check_rate_seconds: 10
 controller_vsphere_incremental_backup: true
 controller_ovirt_warm_migration: true
 controller_max_vm_inflight: 20
+controller_filesystem_overhead: 10
 profiler_volume_path: "/var/cache/profiler"
 
 inventory_volume_path: "/var/cache/inventory"

operator/roles/forkliftcontroller/templates/controller/deployment-controller.yml.j2

@@ -76,6 +76,10 @@ spec:
         - name: CDI_EXPORT_TOKEN_TTL
           value: "{{ CDI_EXPORT_TOKEN_TTL }}"
 {% endif %}
+{% if controller_filesystem_overhead is number %}
+        - name: FILESYSTEM_OVERHEAD
+          value: "{{ controller_filesystem_overhead }}"
+{% endif %}
 {% if controller_vsphere_incremental_backup|bool %}
         - name: FEATURE_VSPHERE_INCREMENTAL_BACKUP
           value: "true"

pkg/controller/plan/adapter/openstack/builder.go

@@ -1100,7 +1100,7 @@ func (r *Builder) persistentVolumeClaimWithSourceRef(image model.Image, storageC
 	}
 
 	if *volumeMode == core.PersistentVolumeFilesystem {
-		virtualSize = utils.CalculateSpaceWithOverhead(virtualSize, 0.1)
+		virtualSize = utils.CalculateSpaceWithOverhead(virtualSize)
 	}
 
 	// The image might be a VM Snapshot Image and has no volume associated to it

pkg/controller/plan/adapter/ovirt/builder.go

@@ -783,6 +783,7 @@ func (r *Builder) persistentVolumeClaimWithSourceRef(diskAttachment model.XDiskA
 	annotations map[string]string) (pvc *core.PersistentVolumeClaim, err error) {
 
 	// We add 10% overhead because of the fsOverhead in CDI, around 5% to ext4 and 5% for root partition.
+	// This value is configurable using `FILESYSTEM_OVERHEAD`
 	diskSize := diskAttachment.Disk.ProvisionedSize
 
 	var accessModes []core.PersistentVolumeAccessMode
@@ -796,7 +797,7 @@ func (r *Builder) persistentVolumeClaimWithSourceRef(diskAttachment model.XDiskA
 	// Accounting for fsOverhead is only required for `volumeMode: Filesystem`, as we may not have enough space
 	// after creating a filesystem on an underlying block device
 	if *volumeMode == core.PersistentVolumeFilesystem {
-		diskSize = utils.CalculateSpaceWithOverhead(diskSize, 0.1)
+		diskSize = utils.CalculateSpaceWithOverhead(diskSize)
 	}
 
 	annotations[AnnImportDiskId] = diskAttachment.ID

pkg/controller/plan/util/BUILD.bazel

@@ -13,6 +13,7 @@ go_library(
         "//pkg/apis/forklift/v1beta1",
         "//pkg/controller/provider/web/openstack",
         "//pkg/controller/provider/web/ovirt",
+        "//pkg/settings",
         "//vendor/k8s.io/api/core/v1:core",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:meta",
     ],

pkg/controller/plan/util/utils.go

@@ -1,6 +1,10 @@
 package util
 
-import "math"
+import (
+	"math"
+
+	"github.com/konveyor/forklift-controller/pkg/settings"
+)
 
 // Disk alignment size used to align FS overhead,
 // its a multiple of all known hardware block sizes 512/4k/8k/32k/64k
@@ -16,8 +20,8 @@ func roundUp(requestedSpace, multiple int64) int64 {
 	return int64(partitions) * multiple
 }
 
-func CalculateSpaceWithOverhead(requestedSpace int64, filesystemOverhead float64) int64 {
+func CalculateSpaceWithOverhead(requestedSpace int64) int64 {
 	alignedSize := roundUp(requestedSpace, DefaultAlignBlockSize)
-	spaceWithOverhead := int64(math.Ceil(float64(alignedSize) / (1 - filesystemOverhead)))
+	spaceWithOverhead := int64(math.Ceil(float64(alignedSize) / (1 - float64(settings.Settings.FileSystemOverhead)/100)))
 	return spaceWithOverhead
 }

pkg/settings/migration.go

@@ -18,6 +18,7 @@ const (
 	SnapshotRemovalTimeout  = "SNAPSHOT_REMOVAL_TIMEOUT"
 	SnapshotStatusCheckRate = "SNAPSHOT_STATUS_CHECK_RATE"
 	CDIExportTokenTTL       = "CDI_EXPORT_TOKEN_TTL"
+	FileSystemOverhead      = "FILESYSTEM_OVERHEAD"
 )
 
 // Default virt-v2v image.
@@ -46,6 +47,8 @@ type Migration struct {
 	VirtV2vDontRequestKVM bool
 	// OCP Export token TTL minutes
 	CDIExportTokenTTL int
+	// FileSystem overhead in percantage
+	FileSystemOverhead int
 }
 
 // Load settings.
@@ -87,11 +90,14 @@ func (r *Migration) Load() (err error) {
 		r.VirtV2vImageWarm = DefaultVirtV2vImage
 	}
 	r.VirtV2vDontRequestKVM = getEnvBool(VirtV2vDontRequestKVM, false)
-
 	r.CDIExportTokenTTL, err = getEnvLimit(CDIExportTokenTTL, 0)
 	if err != nil {
 		err = liberr.Wrap(err)
 	}
+	r.FileSystemOverhead, err = getEnvLimitMinimal(FileSystemOverhead, 10, 0)
+	if err != nil {
+		err = liberr.Wrap(err)
+	}
 
 	return
 }

pkg/settings/settings.go

@@ -2,6 +2,7 @@ package settings
 
 import (
 	liberr "github.com/konveyor/forklift-controller/pkg/lib/error"
+	"fmt"
 	"os"
 	"strconv"
 )
@@ -70,14 +71,20 @@ func (r *ControllerSettings) Load() error {
 // Get positive integer limit from the environment
 // using the specified variable name and default.
 func getEnvLimit(name string, def int) (int, error) {
+	return getEnvLimitMinimal(name, def, 1)
+}
+
+// Get an integer limit from the environment
+// using the specified variable name and default.
+func getEnvLimitMinimal(name string, def, minimum int) (int, error) {
 	limit := 0
 	if s, found := os.LookupEnv(name); found {
 		n, err := strconv.Atoi(s)
 		if err != nil {
 			return 0, liberr.New(name + " must be an integer")
 		}
-		if n < 1 {
-			return 0, liberr.New(name + " must be >= 1")
+		if n < minimum {
+			return 0, liberr.New(fmt.Sprintf(name + " must be >= %d", minimum))
 		}
 		limit = n
 	} else {