diff --git a/pkg/compute/guestdrivers/kvm.go b/pkg/compute/guestdrivers/kvm.go
index f74de59fac..ecbff43f9b 100644
--- a/pkg/compute/guestdrivers/kvm.go
+++ b/pkg/compute/guestdrivers/kvm.go
@@ -375,6 +375,9 @@ func (self *SKVMGuestDriver) GetDeployStatus() ([]string, error) {
 }
 
 func (self *SKVMGuestDriver) ValidateResizeDisk(guest *models.SGuest, disk *models.SDisk, storage *models.SStorage) error {
+	if guest.GetDiskIndex(disk.Id) <= 0 && guest.Status == api.VM_RUNNING {
+		return fmt.Errorf("Cann't online resize root disk")
+	}
 	if !utils.IsInStringArray(guest.Status, []string{api.VM_READY, api.VM_RUNNING}) {
 		return fmt.Errorf("Cannot resize disk when guest in status %s", guest.Status)
 	}
diff --git a/pkg/compute/models/guests.go b/pkg/compute/models/guests.go
index c0f45d8c8e..5e9ab884b7 100644
--- a/pkg/compute/models/guests.go
+++ b/pkg/compute/models/guests.go
@@ -4865,3 +4865,12 @@ func (self *SGuestManager) checkGuestImage(ctx context.Context, input *api.Serve
 	}
 	return nil
 }
+
+func (self *SGuest) GetDiskIndex(diskId string) int8 {
+	for _, gd := range self.GetDisks() {
+		if gd.DiskId == diskId {
+			return gd.Index
+		}
+	}
+	return -1
+}
diff --git a/pkg/hostman/diskutils/nbd/nbdman.go b/pkg/hostman/diskutils/nbd/nbdman.go
index 81a13269b9..4a96dbc86e 100644
--- a/pkg/hostman/diskutils/nbd/nbdman.go
+++ b/pkg/hostman/diskutils/nbd/nbdman.go
@@ -30,23 +30,27 @@ type SNBDManager struct {
 
 var nbdManager *SNBDManager
 
-func Init() {
-	nbdManager = NewNBDManager()
+func Init() error {
+	var err error
+	nbdManager, err = NewNBDManager()
+	return err
 }
 
 func GetNBDManager() *SNBDManager {
 	return nbdManager
 }
 
-func NewNBDManager() *SNBDManager {
+func NewNBDManager() (*SNBDManager, error) {
 	var ret = new(SNBDManager)
 	ret.nbdDevs = make(map[string]bool, 0)
 	ret.nbdLock = new(sync.Mutex)
-	ret.findNbdDevices()
-	return ret
+	if err := ret.findNbdDevices(); err != nil {
+		return ret, err
+	}
+	return ret, nil
 }
 
-func (m *SNBDManager) findNbdDevices() {
+func (m *SNBDManager) findNbdDevices() error {
 	var i = 0
 	for {
 		if fileutils2.Exists(fmt.Sprintf("/dev/nbd%d", i)) {
@@ -57,6 +61,10 @@ func (m *SNBDManager) findNbdDevices() {
 		}
 	}
 	log.Infof("NBD_DEVS: %#v", m.nbdDevs)
+	if len(m.nbdDevs) == 0 {
+		return fmt.Errorf("No nbd devices found")
+	}
+	return nil
 }
 
 func (m *SNBDManager) AcquireNbddev() string {
diff --git a/pkg/hostman/host_services.go b/pkg/hostman/host_services.go
index bce17bf889..6f55941e8c 100644
--- a/pkg/hostman/host_services.go
+++ b/pkg/hostman/host_services.go
@@ -82,7 +82,6 @@ func (host *SHostService) RunService() {
 	guestman.Init(hostInstance, options.HostOptions.ServersPath)
 	app_common.InitAuth(&options.HostOptions.CommonOptions, func() {
 		log.Infof("Auth complete!!")
-		// ??? Why wait 5 seconds
 
 		hostInstance.StartRegister(2, func() {
 			guestman.GetGuestManager().Bootstrap()
@@ -92,10 +91,8 @@ func (host *SHostService) RunService() {
 		})
 	})
 
-	go func() {
-		<-hostinfo.Instance().IsRegistered // wait host and guest init
-		host.initHandlers(app)
-	}()
+	<-hostinfo.Instance().IsRegistered // wait host and guest init
+	host.initHandlers(app)
 
 	// Init Metadata handler
 	go metadata.StartService(
diff --git a/pkg/hostman/hostdeployer/deployserver/deployserver.go b/pkg/hostman/hostdeployer/deployserver/deployserver.go
index fe69345991..2f17ad7d3c 100644
--- a/pkg/hostman/hostdeployer/deployserver/deployserver.go
+++ b/pkg/hostman/hostdeployer/deployserver/deployserver.go
@@ -228,9 +228,12 @@ func (s *SDeployService) PrepareEnv() error {
 	}
 	output, err = procutils.NewCommand("modprobe", "nbd", "max_part=16").Run()
 	if err != nil {
-		log.Errorf("Failed to activate nbd device: %s", output)
+		return fmt.Errorf("Failed to activate nbd device: %s", output)
+	}
+	err = nbd.Init()
+	if err != nil {
+		return err
 	}
-	nbd.Init()
 
 	// https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-bdi
 	for i := 0; i < 16; i++ {
diff --git a/pkg/hostman/hostinfo/hostinfo.go b/pkg/hostman/hostinfo/hostinfo.go
index 229b7ebe05..0956c0620b 100644
--- a/pkg/hostman/hostinfo/hostinfo.go
+++ b/pkg/hostman/hostinfo/hostinfo.go
@@ -569,7 +569,8 @@ func (h *SHostInfo) register() {
 	}
 }
 
-func (h *SHostInfo) onFail() {
+func (h *SHostInfo) onFail(reason interface{}) {
+	log.Errorf("register failed: %s", reason)
 	h.StartRegister(30, nil)
 	panic("register failed, try 30 seconds later...")
 }
@@ -579,8 +580,7 @@ func (h *SHostInfo) tryCreateNetworkOnWire() {
 	masterIp, mask := h.GetMasterNicIpAndMask()
 	log.Debugf("Get master ip %s and mask %d", masterIp, mask)
 	if len(masterIp) == 0 || mask == 0 {
-		log.Errorf("master ip %s mask %d", masterIp, mask)
-		h.onFail()
+		h.onFail(fmt.Sprintf("master ip %s mask %d", masterIp, mask))
 	}
 	params := jsonutils.NewDict()
 	params.Set("ip", jsonutils.NewString(masterIp))
@@ -591,17 +591,14 @@ func (h *SHostInfo) tryCreateNetworkOnWire() {
 		hostutils.GetComputeSession(context.Background()),
 		"try-create-network", params)
 	if err != nil {
-		log.Errorf("try create network get error %s", err)
-		h.onFail()
+		h.onFail(fmt.Sprintf("try create network get error %s", err))
 	}
 	if !jsonutils.QueryBoolean(ret, "find_matched", false) {
-		log.Errorf("Fail to get network info: no networks")
-		h.onFail()
+		h.onFail(fmt.Sprintf("try create network get error %s", err))
 	}
 	wireId, err := ret.GetString("wire_id")
 	if err != nil {
-		log.Errorf("Fail to get network info: no wire id")
-		h.onFail()
+		h.onFail(fmt.Sprintf("try create network get error %s", err))
 	}
 	h.onGetWireId(wireId)
 }
@@ -609,7 +606,7 @@ func (h *SHostInfo) tryCreateNetworkOnWire() {
 func (h *SHostInfo) fetchAccessNetworkInfo() {
 	masterIp := h.GetMasterIp()
 	if len(masterIp) == 0 {
-		panic("master ip not found")
+		h.onFail("master ip not found")
 	}
 	log.Debugf("Master ip %s to fetch wire", masterIp)
 	params := jsonutils.NewDict()
@@ -619,8 +616,7 @@ func (h *SHostInfo) fetchAccessNetworkInfo() {
 
 	res, err := modules.Networks.List(h.GetSession(), params)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	}
 	if len(res.Data) == 0 {
 		h.tryCreateNetworkOnWire()
@@ -628,21 +624,18 @@ func (h *SHostInfo) fetchAccessNetworkInfo() {
 		wireId, _ := res.Data[0].GetString("wire_id")
 		h.onGetWireId(wireId)
 	} else {
-		log.Errorf("Fail to get network info: no networks")
-		h.onFail()
+		h.onFail("Fail to get network info: no networks")
 	}
 }
 
 func (h *SHostInfo) onGetWireId(wireId string) {
 	wire, err := hostutils.GetWireInfo(context.Background(), wireId)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	}
 	h.ZoneId, err = wire.GetString("zone_id")
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		h.getZoneInfo(h.ZoneId, false)
 	}
@@ -659,8 +652,7 @@ func (h *SHostInfo) getZoneInfo(zoneId string, standalone bool) {
 	res, err := modules.Zones.Get(h.GetSession(),
 		zoneId, params)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	}
 
 	h.Zone, _ = res.GetString("name")
@@ -678,14 +670,13 @@ func (h *SHostInfo) getZoneInfo(zoneId string, standalone bool) {
 func (h *SHostInfo) getHostInfo(zoneId string) {
 	masterMac := h.getMasterMacWithRefresh(true)
 	if len(masterMac) == 0 {
-		panic("master mac not found")
+		h.onFail("master mac not found")
 	}
 	params := jsonutils.NewDict()
 	params.Set("any_mac", jsonutils.NewString(masterMac))
 	res, err := modules.Hosts.List(h.GetSession(), params)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	}
 	if len(res.Data) == 0 {
 		h.updateHostRecord("")
@@ -740,7 +731,7 @@ func (h *SHostInfo) updateHostRecord(hostId string) {
 	content := jsonutils.NewDict()
 	masterIp := h.GetMasterIp()
 	if len(masterIp) == 0 {
-		panic("master ip is none")
+		h.onFail("master ip is none")
 	}
 
 	if len(hostId) == 0 {
@@ -795,8 +786,7 @@ func (h *SHostInfo) updateHostRecord(hostId string) {
 		res, err = modules.Hosts.CreateInContext(h.GetSession(), content, &modules.Zones, h.ZoneId)
 	}
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		h.onUpdateHostInfoSucc(res)
 	}
@@ -819,8 +809,7 @@ func (h *SHostInfo) updateHostReservedMem() {
 	res, err := modules.Hosts.Update(h.GetSession(),
 		h.HostId, content)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		h.onUpdateHostInfoSucc(res)
 	}
@@ -841,8 +830,7 @@ func (h *SHostInfo) PutHostOffline() {
 	_, err := modules.Hosts.PerformAction(
 		h.GetSession(), h.HostId, "offline", nil)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		h.getNetworkInfo()
 	}
@@ -863,8 +851,7 @@ func (h *SHostInfo) getNetworkInfo() {
 		h.GetSession(),
 		h.HostId, params)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		for _, hostwire := range res.Data {
 			bridge, _ := hostwire.GetString("bridge")
@@ -898,8 +885,7 @@ func (h *SHostInfo) uploadNetworkInfo() {
 
 				wireInfo, err := hostutils.GetWireOfIp(context.Background(), kwargs)
 				if err != nil {
-					log.Errorln(err)
-					h.onFail()
+					h.onFail(err)
 				} else {
 					nic.Network, _ = wireInfo.GetString("name")
 					h.doUploadNicInfo(nic)
@@ -934,8 +920,7 @@ func (h *SHostInfo) doUploadNicInfo(nic *SNIC) {
 	_, err := modules.Hosts.PerformAction(h.GetSession(),
 		h.HostId, "add-netif", content)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		h.onUploadNicInfoSucc(nic)
 	}
@@ -950,16 +935,14 @@ func (h *SHostInfo) doSyncNicInfo(nic *SNIC) {
 	_, err := modules.Hostwires.Update(h.GetSession(),
 		h.HostId, nic.WireId, query, content)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	}
 }
 
 func (h *SHostInfo) onUploadNicInfoSucc(nic *SNIC) {
 	res, err := modules.Hostwires.Get(h.GetSession(), h.HostId, nic.Network, nil)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		bridge, _ := res.GetString("bridge")
 		iface, _ := res.GetString("interface")
@@ -974,8 +957,7 @@ func (h *SHostInfo) onUploadNicInfoSucc(nic *SNIC) {
 			}
 			nic.SetWireId(wire, wireId, bandwidth)
 		} else {
-			log.Errorln("GetMatchNic failed!!!")
-			h.onFail()
+			h.onFail("GetMatchNic failed!!!")
 		}
 	}
 }
@@ -988,8 +970,7 @@ func (h *SHostInfo) getStoragecacheInfo() {
 	res, err := modules.Storagecaches.List(
 		h.GetSession(), params)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		if len(res.Data) == 0 {
 			body := jsonutils.NewDict()
@@ -1000,8 +981,7 @@ func (h *SHostInfo) getStoragecacheInfo() {
 			body.Set("external_id", jsonutils.NewString(h.HostId))
 			sc, err := modules.Storagecaches.Create(h.GetSession(), body)
 			if err != nil {
-				log.Errorln(err)
-				h.onFail()
+				h.onFail(err)
 			} else {
 				scid, _ := sc.GetString("id")
 				storageman.GetManager().
@@ -1025,8 +1005,7 @@ func (h *SHostInfo) getStorageInfo() {
 		h.GetSession(),
 		h.HostId, params)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	} else {
 		h.onGetStorageInfoSucc(res.Data)
 	}
@@ -1082,8 +1061,7 @@ func (h *SHostInfo) uploadStorageInfo() {
 	for _, s := range storageman.GetManager().Storages {
 		res, err := s.SyncStorageInfo()
 		if err != nil {
-			log.Errorln(err)
-			h.onFail()
+			h.onFail(err)
 		} else {
 			h.onSyncStorageInfoSucc(s, res)
 		}
@@ -1107,8 +1085,7 @@ func (h *SHostInfo) attachStorage(storage storageman.IStorage) {
 	_, err := modules.Hoststorages.Attach(h.GetSession(),
 		h.HostId, storage.GetId(), content)
 	if err != nil {
-		log.Errorln(err)
-		h.onFail()
+		h.onFail(err)
 	}
 }
 
@@ -1119,9 +1096,7 @@ func (h *SHostInfo) getIsolatedDevices() {
 	params.Set("host", jsonutils.NewString(h.GetHostId()))
 	res, err := modules.IsolatedDevices.List(h.GetSession(), params)
 	if err != nil {
-		log.Errorf("getIsolatedDevices: %v", err)
-		h.onFail()
-		return
+		h.onFail(fmt.Sprintf("getIsolatedDevices: %v", err))
 	}
 	h.onGetIsolatedDeviceSucc(res.Data)
 }
@@ -1140,9 +1115,7 @@ func (h *SHostInfo) onGetIsolatedDeviceSucc(objs []jsonutils.JSONObject) {
 	}
 	h.IsolatedDeviceMan.StartDetachTask()
 	if err := h.IsolatedDeviceMan.BatchCustomProbe(); err != nil {
-		log.Errorf("Device probe error: %v", err)
-		h.onFail()
-		return
+		h.onFail(fmt.Sprintf("Device probe error: %v", err))
 	}
 	h.uploadIsolatedDevices()
 }
@@ -1150,9 +1123,7 @@ func (h *SHostInfo) onGetIsolatedDeviceSucc(objs []jsonutils.JSONObject) {
 func (h *SHostInfo) uploadIsolatedDevices() {
 	for _, dev := range h.IsolatedDeviceMan.Devices {
 		if err := dev.SyncDeviceInfo(h); err != nil {
-			log.Errorf("Sync device %s: %v", dev.String(), err)
-			h.onFail()
-			return
+			h.onFail(fmt.Sprintf("Sync device %s: %v", dev.String(), err))
 		}
 	}
 	h.deployAdminAuthorizedKeys()
@@ -1160,8 +1131,7 @@ func (h *SHostInfo) uploadIsolatedDevices() {
 
 func (h *SHostInfo) deployAdminAuthorizedKeys() {
 	onErr := func(format string, args ...interface{}) {
-		log.Errorf(format, args...)
-		h.onFail()
+		h.onFail(fmt.Sprintf(format, args...))
 	}
 
 	sshDir := path.Join("/root", ".ssh")
@@ -1169,7 +1139,6 @@ func (h *SHostInfo) deployAdminAuthorizedKeys() {
 		if os.IsNotExist(err) {
 			if err := os.MkdirAll(sshDir, 0755); err != nil {
 				onErr("Create ssh dir %s: %v", sshDir, err)
-				return
 			}
 		} else {
 			onErr("Stat %s dir: %v", sshDir, err)
@@ -1181,11 +1150,9 @@ func (h *SHostInfo) deployAdminAuthorizedKeys() {
 	ret, err := modules.Sshkeypairs.List(h.GetSession(), query)
 	if err != nil {
 		onErr("Get admin sshkey: %v", err)
-		return
 	}
 	if len(ret.Data) == 0 {
 		onErr("Not found admin sshkey")
-		return
 	}
 	keys := ret.Data[0]
 	adminPublicKey, _ := keys.GetString("public_key")
@@ -1197,11 +1164,9 @@ func (h *SHostInfo) deployAdminAuthorizedKeys() {
 	newKeys := fsdriver.MergeAuthorizedKeys(oldKeys, pubKeys)
 	if err := fileutils2.FilePutContents(authFile, newKeys, false); err != nil {
 		onErr("Write public keys: %v", err)
-		return
 	}
 	if err := os.Chmod(authFile, 0644); err != nil {
 		onErr("Chmod %s to 0644: %v", authFile, err)
-		return
 	}
 	h.onSucc()
 }
diff --git a/pkg/hostman/hostinfo/hostinfohelper.go b/pkg/hostman/hostinfo/hostinfohelper.go
index 1464f5d33b..36a8c1b958 100644
--- a/pkg/hostman/hostinfo/hostinfohelper.go
+++ b/pkg/hostman/hostinfo/hostinfohelper.go
@@ -256,7 +256,6 @@ func NewNIC(desc string) (*SNIC, error) {
 	nic.Bandwidth = 1000
 
 	log.Infof("IP %s/%s/%s", nic.Ip, nic.Bridge, nic.Inter)
-	// 这是干啥呢 ？？？
 	if len(nic.Ip) > 0 {
 		var max, wait = 30, 0
 		for wait < max {