diff --git a/pkg/api/types.go b/pkg/api/types.go
index 9b533a0..5cfd965 100644
--- a/pkg/api/types.go
+++ b/pkg/api/types.go
@@ -19,7 +19,7 @@ import (
 	"errors"
 	"sync"
 
-	"github.com/satori/go.uuid"
+	uuid "github.com/satori/go.uuid"
 )
 
 type SCSICommandType byte
@@ -351,6 +351,7 @@ type BackingStore interface {
 	Write([]byte, int64) error
 	DataSync() error
 	DataAdvise(int64, int64, uint32) error
+	Unmap() error
 }
 
 type SCSIDeviceProtocol interface {
diff --git a/pkg/config/config.go b/pkg/config/config.go
index 092b81f..8aa95b9 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -101,9 +101,11 @@ var (
 )
 
 type BackendStorage struct {
-	DeviceID uint64 `json:"deviceID"`
-	Path     string `json:"path"`
-	Online   bool   `json:"online"`
+	DeviceID         uint64 `json:"deviceID"`
+	Path             string `json:"path"`
+	Online           bool   `json:"online"`
+	Thinprovisioning bool   `json:"thinprovisioning"`
+	BlockShift       uint   `json:"blockShift"`
 }
 
 type ISCSIPortalInfo struct {
diff --git a/pkg/scsi/backingstore.go b/pkg/scsi/backingstore.go
index 7cf0315..6dcb541 100644
--- a/pkg/scsi/backingstore.go
+++ b/pkg/scsi/backingstore.go
@@ -135,7 +135,11 @@ func bsPerformCommand(bs api.BackingStore, cmd *api.SCSICommand) (err error, key
 		doVerify = true
 		goto verify
 	case api.UNMAP:
-		// TODO
+		err = bs.Unmap()
+		if err != nil {
+			key = MEDIUM_ERROR
+			asc = NO_ADDITIONAL_SENSE
+		}
 	default:
 		break
 	}
diff --git a/pkg/scsi/backingstore/cephstore_linux.go b/pkg/scsi/backingstore/cephstore_linux.go
index 291283a..c77820a 100644
--- a/pkg/scsi/backingstore/cephstore_linux.go
+++ b/pkg/scsi/backingstore/cephstore_linux.go
@@ -149,3 +149,7 @@ func (bs *CephBackingStore) DataSync() error {
 func (bs *CephBackingStore) DataAdvise(offset, length int64, advise uint32) error {
 	return nil
 }
+
+func (bs *CephBackingStore) Unmap() error {
+	return nil
+}
diff --git a/pkg/scsi/backingstore/common.go b/pkg/scsi/backingstore/common.go
index 4d78fab..fc35bad 100644
--- a/pkg/scsi/backingstore/common.go
+++ b/pkg/scsi/backingstore/common.go
@@ -113,3 +113,7 @@ func (bs *FileBackingStore) DataSync() error {
 func (bs *FileBackingStore) DataAdvise(offset, length int64, advise uint32) error {
 	return util.Fadvise(bs.file, offset, length, advise)
 }
+
+func (bs *FileBackingStore) Unmap() error {
+	return nil
+}
diff --git a/pkg/scsi/backingstore/null.go b/pkg/scsi/backingstore/null.go
index 2cbde02..f718d9a 100644
--- a/pkg/scsi/backingstore/null.go
+++ b/pkg/scsi/backingstore/null.go
@@ -74,3 +74,7 @@ func (bs *NullBackingStore) DataSync() error {
 func (bs *NullBackingStore) DataAdvise(offset, length int64, advise uint32) error {
 	return nil
 }
+
+func (bs *NullBackingStore) Unmap() error {
+	return nil
+}
diff --git a/pkg/scsi/lun.go b/pkg/scsi/lun.go
index a7a8afa..790377d 100644
--- a/pkg/scsi/lun.go
+++ b/pkg/scsi/lun.go
@@ -20,13 +20,13 @@ import (
 	"strings"
 
 	"github.com/gostor/gotgt/pkg/api"
+	"github.com/gostor/gotgt/pkg/config"
 )
 
 // NewSCSILu: create a new SCSI LU
 // path format <protocol>:/absolute/file/path
-func NewSCSILu(device_uuid uint64, path string, online bool) (*api.SCSILu, error) {
-
-	pathinfo := strings.SplitN(path, ":", 2)
+func NewSCSILu(bs *config.BackendStorage) (*api.SCSILu, error) {
+	pathinfo := strings.SplitN(bs.Path, ":", 2)
 	if len(pathinfo) < 2 {
 		return nil, errors.New("invalid device path string")
 	}
@@ -43,8 +43,8 @@ func NewSCSILu(device_uuid uint64, path string, online bool) (*api.SCSILu, error
 		PerformCommand: luPerformCommand,
 		DeviceProtocol: sbc,
 		Storage:        backing,
-		BlockShift:     api.DefaultBlockShift,
-		UUID:           device_uuid,
+		BlockShift:     bs.BlockShift,
+		UUID:           bs.DeviceID,
 	}
 
 	err = backing.Open(lu, backendPath)
@@ -53,7 +53,8 @@ func NewSCSILu(device_uuid uint64, path string, online bool) (*api.SCSILu, error
 	}
 	lu.Size = backing.Size(lu)
 	lu.DeviceProtocol.InitLu(lu)
-	lu.Attrs.Online = online
+	lu.Attrs.Thinprovisioning = bs.Thinprovisioning
+	lu.Attrs.Online = bs.Online
 	lu.Attrs.Lbppbe = 3
 	return lu, nil
 }
diff --git a/pkg/scsi/sbc.go b/pkg/scsi/sbc.go
index ad54aec..36e668e 100644
--- a/pkg/scsi/sbc.go
+++ b/pkg/scsi/sbc.go
@@ -295,7 +295,13 @@ sense:
 }
 
 func SBCUnmap(host int, cmd *api.SCSICommand) api.SAMStat {
-	return api.SAMStatGood
+	err, key, asc := bsPerformCommand(cmd.Device.Storage, cmd)
+	if err == nil {
+		return api.SAMStatGood
+	}
+
+	BuildSenseData(cmd, key, asc)
+	return api.SAMStatCheckCondition
 }
 
 /*
@@ -594,7 +600,11 @@ func SBCReadCapacity16(host int, cmd *api.SCSICommand) api.SAMStat {
 	if allocationLength > 12 {
 		copy(cmd.InSDBBuffer.Buffer[8:], util.MarshalUint32(uint32(1<<bshift)))
 		if allocationLength > 16 {
-			val := (cmd.Device.Attrs.Lbppbe << 16) | cmd.Device.Attrs.LowestAlignedLBA
+			var lbpme int
+			if cmd.Device.Attrs.Thinprovisioning {
+				lbpme = 1
+			}
+			val := (cmd.Device.Attrs.Lbppbe << 16) | (lbpme << 15) | cmd.Device.Attrs.LowestAlignedLBA
 			copy(cmd.InSDBBuffer.Buffer[12:], util.MarshalUint32(uint32(val)))
 		}
 	}
diff --git a/pkg/scsi/scsilumap.go b/pkg/scsi/scsilumap.go
index 5803507..a968eef 100644
--- a/pkg/scsi/scsilumap.go
+++ b/pkg/scsi/scsilumap.go
@@ -73,7 +73,7 @@ func InitSCSILUMap(config *config.Config) error {
 	defer globalSCSILUMap.mutex.Unlock()
 
 	for _, bs := range config.Storages {
-		lu, err := NewSCSILu(bs.DeviceID, bs.Path, bs.Online)
+		lu, err := NewSCSILu(&bs)
 		if err != nil {
 			return fmt.Errorf("Init SCSI LU map error: %v", err)
 		}
diff --git a/pkg/scsi/spc.go b/pkg/scsi/spc.go
index cc1bc7e..41b403c 100644
--- a/pkg/scsi/spc.go
+++ b/pkg/scsi/spc.go
@@ -25,7 +25,7 @@ import (
 	log "github.com/Sirupsen/logrus"
 	"github.com/gostor/gotgt/pkg/api"
 	"github.com/gostor/gotgt/pkg/util"
-	"github.com/satori/go.uuid"
+	uuid "github.com/satori/go.uuid"
 )
 
 func SPCIllegalOp(host int, cmd *api.SCSICommand) api.SAMStat {
@@ -58,6 +58,7 @@ func InquiryPage0x00(host int, cmd *api.SCSICommand) (*bytes.Buffer, uint16) {
 	descBuf.WriteByte(0x00)
 	descBuf.WriteByte(0x80)
 	descBuf.WriteByte(0x83)
+	descBuf.WriteByte(0xB0)
 	/*
 		TODO:
 			descBuf.WriteByte(0x86)
@@ -188,6 +189,42 @@ func InquiryPage0x83(host int, cmd *api.SCSICommand) (*bytes.Buffer, uint16) {
 	return buf, pageLength
 }
 
+func InquiryPage0xB0(host int, cmd *api.SCSICommand) (*bytes.Buffer, uint16) {
+	var (
+		buf                                 = &bytes.Buffer{}
+		pageLength                   uint16 = 0x3C
+		maxUnmapLbaCount             uint32 = 0
+		maxUnmapBlockDescriptorCount uint32 = 0
+	)
+
+	if cmd.Device.Attrs.Thinprovisioning {
+		maxUnmapLbaCount = 0xFFFFFFFF
+		maxUnmapBlockDescriptorCount = 0xFFFFFFFF
+	}
+
+	//byte 0
+	if cmd.Device.Attrs.Online {
+		buf.WriteByte(PQ_DEVICE_CONNECTED | byte(cmd.Device.Attrs.DeviceType))
+	} else {
+		buf.WriteByte(PQ_DEVICE_NOT_CONNECT | byte(cmd.Device.Attrs.DeviceType))
+	}
+	//PAGE CODE
+	buf.WriteByte(0xB0)
+	//PAGE LENGTH
+	binary.Write(buf, binary.BigEndian, pageLength)
+
+	buf.Write(make([]byte, 16))
+
+	//MAXIMUM UNMAP LBA COUNT
+	binary.Write(buf, binary.BigEndian, maxUnmapLbaCount)
+
+	//MAXIMUM UNMAP BLOCK DESCRIPTOR COUNT
+	binary.Write(buf, binary.BigEndian, maxUnmapBlockDescriptorCount)
+
+	buf.Write(make([]byte, 36))
+	return buf, pageLength
+}
+
 /*
  * SPCInquiry Implements SCSI INQUIRY command
  * The INQUIRY command requests the device server to return information regarding the logical unit and SCSI target device.
@@ -231,6 +268,8 @@ func SPCInquiry(host int, cmd *api.SCSICommand) api.SAMStat {
 			buf, _ = InquiryPage0x80(host, cmd)
 		case 0x83:
 			buf, _ = InquiryPage0x83(host, cmd)
+		case 0xB0:
+			buf, _ = InquiryPage0xB0(host, cmd)
 		default:
 			goto sense
 		}
@@ -610,7 +649,7 @@ func reportOpcodesAll(cmd *api.SCSICommand, rctd int) error {
 	var (
 		data = []byte{0x00, 0x00, 0x00, 0x00}
 	)
-	for _, i := range []api.SCSICommandType{api.TEST_UNIT_READY, api.WRITE_6, api.INQUIRY, api.READ_CAPACITY, api.WRITE_10, api.WRITE_16, api.REPORT_LUNS, api.WRITE_12} {
+	for _, i := range []api.SCSICommandType{api.TEST_UNIT_READY, api.WRITE_6, api.INQUIRY, api.READ_CAPACITY, api.WRITE_10, api.WRITE_16, api.REPORT_LUNS, api.WRITE_12, api.UNMAP} {
 		data = append(data, byte(i))
 		// reserved
 		data = append(data, 0x00)
@@ -627,7 +666,7 @@ func reportOpcodesAll(cmd *api.SCSICommand, rctd int) error {
 		}
 		// cdb length
 		length := getSCSICmdSize(i)
-		data = append(data, (length>>8)&0xff)
+		data = append(data, 0)
 		data = append(data, length&0xff)
 		// timeout descriptor
 		if rctd != 0 {