diff --git a/pkg/compute/models/guest_actions.go b/pkg/compute/models/guest_actions.go
index c20d1ad85c..d6aa054b23 100644
--- a/pkg/compute/models/guest_actions.go
+++ b/pkg/compute/models/guest_actions.go
@@ -798,7 +798,39 @@ func (self *SGuest) StartInsertIsoTask(ctx context.Context, imageId string, host
 	return nil
 }
 
-func (self *SGuest) StartGueststartTask(ctx context.Context, userCred mcclient.TokenCredential, data *jsonutils.JSONDict, parentTaskId string) error {
+func (self *SGuest) IsDisksShared() bool {
+	return self.getDefaultStorageType() == api.STORAGE_RBD
+}
+
+func (self *SGuest) StartGueststartTask(
+	ctx context.Context, userCred mcclient.TokenCredential,
+	data *jsonutils.JSONDict, parentTaskId string,
+) error {
+	if self.Hypervisor == api.HYPERVISOR_KVM && self.IsDisksShared() {
+		return self.GuestSchedStartTask(ctx, userCred, data, parentTaskId)
+	} else {
+		return self.GuestNonSchedStartTask(ctx, userCred, data, parentTaskId)
+	}
+}
+
+func (self *SGuest) GuestSchedStartTask(
+	ctx context.Context, userCred mcclient.TokenCredential,
+	data *jsonutils.JSONDict, parentTaskId string,
+) error {
+	self.SetStatus(userCred, api.VM_SCHEDULE, "")
+	task, err := taskman.TaskManager.NewTask(ctx, "GuestSchedStartTask", self, userCred, data,
+		parentTaskId, "", nil)
+	if err != nil {
+		return err
+	}
+	task.ScheduleRun(nil)
+	return nil
+}
+
+func (self *SGuest) GuestNonSchedStartTask(
+	ctx context.Context, userCred mcclient.TokenCredential,
+	data *jsonutils.JSONDict, parentTaskId string,
+) error {
 	self.SetStatus(userCred, api.VM_START_START, "")
 	task, err := taskman.TaskManager.NewTask(ctx, "GuestStartTask", self, userCred, data, parentTaskId, "", nil)
 	if err != nil {
diff --git a/pkg/compute/models/hosts.go b/pkg/compute/models/hosts.go
index 68bc1406d5..7019a47e55 100644
--- a/pkg/compute/models/hosts.go
+++ b/pkg/compute/models/hosts.go
@@ -1215,6 +1215,14 @@ func (self *SHost) GetRunningGuestCount() (int, error) {
 	return q.CountWithError()
 }
 
+func (self *SHost) GetRunningGuestMemorySize() int {
+	res := self.getGuestsResource(api.VM_RUNNING)
+	if res != nil {
+		return res.GuestVmemSize
+	}
+	return -1
+}
+
 func (self *SHost) GetBaremetalnetworksQuery() *sqlchemy.SQuery {
 	return HostnetworkManager.Query().Equals("baremetal_id", self.Id)
 }
diff --git a/pkg/compute/tasks/guest_start_task.go b/pkg/compute/tasks/guest_start_task.go
index 00f0e6402e..f3bfffe050 100644
--- a/pkg/compute/tasks/guest_start_task.go
+++ b/pkg/compute/tasks/guest_start_task.go
@@ -154,3 +154,52 @@ func (self *GuestStartTask) taskComplete(ctx context.Context, guest *models.SGue
 	models.HostManager.ClearSchedDescCache(guest.HostId)
 	self.SetStageComplete(ctx, nil)
 }
+
+type GuestSchedStartTask struct {
+	SGuestBaseTask
+}
+
+func (self *GuestSchedStartTask) OnInit(ctx context.Context, obj db.IStandaloneModel, data jsonutils.JSONObject) {
+	guest := obj.(*models.SGuest)
+	self.StartScheduler(ctx, guest)
+}
+
+func (self *GuestSchedStartTask) StartScheduler(ctx context.Context, guest *models.SGuest) {
+	host := guest.GetHost()
+	if guestsMem := host.GetRunningGuestMemorySize(); guestsMem < 0 {
+		self.TaskFailed(ctx, guest, "Guest Start Failed: Can't Get Host Guests Memory")
+	} else {
+		if float32(guestsMem+guest.VmemSize) > host.GetVirtualMemorySize() {
+			self.ScheduleFailed(ctx, guest)
+		} else {
+			self.ScheduleSucc(ctx, guest)
+		}
+	}
+}
+
+func (self *GuestSchedStartTask) ScheduleFailed(ctx context.Context, guest *models.SGuest) {
+	self.SetStage("OnGuestMigrate", nil)
+	guest.StartMigrateTask(ctx, self.UserCred, false, false, guest.Status, "", self.GetId())
+}
+
+func (self *GuestSchedStartTask) OnGuestMigrate(ctx context.Context, guest *models.SGuest, data jsonutils.JSONObject) {
+	self.SetStageComplete(ctx, nil)
+	guest.GuestNonSchedStartTask(ctx, self.UserCred, nil, "")
+}
+
+func (self *GuestSchedStartTask) OnGuestMigrateFailed(ctx context.Context, guest *models.SGuest, data jsonutils.JSONObject) {
+	self.TaskFailed(ctx, guest, fmt.Sprintf("OnGuestMigrateFailed %s", data))
+}
+
+func (self *GuestSchedStartTask) ScheduleSucc(ctx context.Context, guest *models.SGuest) {
+	self.SetStageComplete(ctx, nil)
+	guest.GuestNonSchedStartTask(ctx, self.UserCred, nil, "")
+}
+
+func (self *GuestSchedStartTask) TaskFailed(ctx context.Context, guest *models.SGuest, reason string) {
+	self.SetStageFailed(ctx, reason)
+	guest.SetStatus(self.UserCred, api.VM_START_FAILED, reason)
+	db.OpsLog.LogEvent(guest, db.ACT_START_FAIL, reason, self.UserCred)
+	logclient.AddActionLogWithStartable(
+		self, guest, logclient.ACT_VM_START, reason, self.UserCred, false)
+}