diff --git a/pkg/compute/models/guests.go b/pkg/compute/models/guests.go
index 07c6387e9b..7853b9a3a9 100644
--- a/pkg/compute/models/guests.go
+++ b/pkg/compute/models/guests.go
@@ -2898,15 +2898,16 @@ func (self *SGuest) syncWithCloudVM(ctx context.Context, userCred mcclient.Token
 			self.InstanceType = instanceType
 		}
 
-		if extVM.GetHypervisor() == api.HYPERVISOR_AWS {
-			sku, err := ServerSkuManager.FetchSkuByNameAndProvider(instanceType, api.CLOUD_PROVIDER_AWS, false)
-			if err == nil {
-				self.VmemSize = sku.MemorySizeMB
+		memSizeMb := extVM.GetVmemSizeMB()
+		if self.VmemSize == 0 || self.VmemSize != memSizeMb {
+			if memSizeMb > 0 {
+				self.VmemSize = memSizeMb
 			} else {
-				self.VmemSize = extVM.GetVmemSizeMB()
+				sku, _ := ServerSkuManager.FetchSkuByNameAndProvider(instanceType, provider.GetFactory().GetName(), false)
+				if sku != nil && sku.MemorySizeMB > 0 {
+					self.VmemSize = sku.MemorySizeMB
+				}
 			}
-		} else {
-			self.VmemSize = extVM.GetVmemSizeMB()
 		}
 
 		self.Hypervisor = extVM.GetHypervisor()
diff --git a/pkg/compute/models/skus.go b/pkg/compute/models/skus.go
index ebec1d156b..69c6be08a7 100644
--- a/pkg/compute/models/skus.go
+++ b/pkg/compute/models/skus.go
@@ -639,18 +639,36 @@ func (self *SServerSku) StartServerSkuDeleteTask(ctx context.Context, userCred m
 	return nil
 }
 
+func (self *SServerSku) GetGuestCount() (int, error) {
+	guestsQ := GuestManager.Query().SubQuery()
+	hostsQ := HostManager.Query().SubQuery()
+	zonesQ := ZoneManager.Query().SubQuery()
+	q := guestsQ.Query().
+		Join(hostsQ, sqlchemy.Equals(guestsQ.Field("host_id"), hostsQ.Field("id"))).
+		Join(zonesQ, sqlchemy.Equals(hostsQ.Field("zone_id"), zonesQ.Field("id"))).
+		Filter(sqlchemy.Equals(guestsQ.Field("instance_type"), self.Name))
+	if len(self.ZoneId) > 0 {
+		q = q.Filter(sqlchemy.Equals(hostsQ.Field("zone_id"), self.ZoneId))
+	} else {
+		q = q.Filter(sqlchemy.Equals(zonesQ.Field("cloudregion_id"), self.CloudregionId))
+	}
+	return q.CountWithError()
+}
+
 func (self *SServerSku) ValidateDeleteCondition(ctx context.Context, info *api.ServerSkuDetails) error {
-	if info.TotalGuestCount > 0 {
+	totalGuestCnt := 0
+	if info != nil {
+		totalGuestCnt = info.TotalGuestCount
+	} else {
+		totalGuestCnt, _ = self.GetGuestCount()
+	}
+	if totalGuestCnt > 0 {
 		return httperrors.NewNotEmptyError("now allow to delete inuse instance_type.please remove related servers first: %s", self.Name)
 	}
 
 	if !inWhiteList(self.Provider) {
 		return httperrors.NewForbiddenError("not allow to delete public cloud instance_type: %s", self.Name)
 	}
-	/*count := GuestManager.Query().Equals("instance_type", self.Id).Count()
-	if count > 0 {
-		return httperrors.NewNotEmptyError("instance_type used by servers")
-	}*/
 	return nil
 }
 
@@ -1214,7 +1232,12 @@ func (manager *SServerSkuManager) SyncServerSkus(ctx context.Context, userCred m
 	}
 
 	for i := 0; i < len(removed); i += 1 {
-		err = removed[i].MarkAsSoldout(ctx)
+		cnt, err := removed[i].GetGuestCount()
+		if err != nil || cnt > 0 {
+			err = removed[i].MarkAsSoldout(ctx)
+		} else {
+			err = removed[i].RealDelete(ctx, userCred)
+		}
 		if err != nil {
 			syncResult.DeleteError(err)
 		} else {