diff --git a/filesystem.go b/filesystem.go
index d67a651..a494e8e 100644
--- a/filesystem.go
+++ b/filesystem.go
@@ -16,6 +16,11 @@ import (
 	"github.com/google/uuid"
 	"github.com/spf13/afero"
 )
+import (
+	"fmt"
+	"path/filepath"
+	"strings"
+)
 
 type VirtualizationInstance struct {
 	rootPath        string
@@ -46,7 +51,7 @@ func (instance *VirtualizationInstance) Close() error {
 	return nil
 }
 
-func StartProjecting(rootPath string, filesystem afero.Fs) (io.Closer, error) {
+func StartProjecting(rootPath string, filesystem afero.Fs) (Virtualization, error) {
 	instance := &VirtualizationInstance{
 		enumerations: make(map[syscall.GUID]*enumerationSession),
 	}
@@ -86,18 +91,26 @@ func (instance *VirtualizationInstance) start(rootPath string, filesystem afero.
 		log.Printf("Error starting virtualization: %s", err)
 		return err
 	}
-	return instance.syncRemoteToLcal()
+	return instance.syncRemoteToLocal()
+}
+
+func (instance *VirtualizationInstance) PerformSynchronization() error {
+	err := instance.syncRemoteToLocal()
+	if err != nil {
+		return err
+	}
+	return instance.syncLocalToRemote()
 }
 
-func (instance *VirtualizationInstance) syncRemoteToLcal() error {
-	return afero.Walk(instance.fs, "", func(path string, info fs.FileInfo, err error) error {
+func (instance *VirtualizationInstance) syncRemoteToLocal() error {
+	return afero.Walk(instance.fs, "", func(path string, remoteinfo fs.FileInfo, err error) error {
 		if os.IsNotExist(err) {
 			return nil
 		}
 		if err != nil {
 			return err
 		}
-		if info.IsDir() {
+		if remoteinfo.IsDir() {
 			return nil
 		}
 		localpath := instance.rootPath + "\\" + path
@@ -107,13 +120,18 @@ func (instance *VirtualizationInstance) syncRemoteToLcal() error {
 			return projfs.ErrorByCode(hr)
 		}
 
-		if localstate == projfs.PRJ_FILE_STATE_FULL {
+		if (localstate | (projfs.PRJ_FILE_STATE_FULL & projfs.PRJ_FILE_STATE_HYDRATED_PLACEHOLDER)) != 0 {
 			// check if remote is newer
 			localinfo, _ := os.Stat(localpath)
-			if localinfo.ModTime().UTC().Unix() > info.ModTime().UTC().Unix() {
+			if localinfo.ModTime().UTC().Unix() < remoteinfo.ModTime().UTC().Unix() {
+				log.Printf("Updating local file '%s'", path)
 				var placeholderInfo projfs.PRJ_PLACEHOLDER_INFO
-				placeholderInfo.FileBasicInfo = toBasicInfo(info)
-				instance.UpdateFileIfNeeded(path, &placeholderInfo, uint32(info.Size()), projfs.PRJ_UPDATE_ALLOW_DIRTY_METADATA, nil)
+				FillInPlaceholderInfo(&placeholderInfo, remoteinfo)
+				//err = projfs.ErrorByCode(projfs.PrjWritePlaceholderInfo(instance._instanceHandle, path, &placeholderInfo, uint32(unsafe.Sizeof(placeholderInfo))))
+				err = instance.UpdateFileIfNeeded(path, &placeholderInfo, uint32(unsafe.Sizeof(placeholderInfo)), projfs.PRJ_UPDATE_ALLOW_DIRTY_METADATA|projfs.PRJ_UPDATE_ALLOW_DIRTY_DATA)
+				if err != nil {
+					return err
+				}
 			}
 		}
 
@@ -121,6 +139,58 @@ func (instance *VirtualizationInstance) syncRemoteToLcal() error {
 	})
 }
 
+func (instance *VirtualizationInstance) syncLocalToRemote() error {
+	return filepath.Walk(instance.rootPath, func(localpath string, localinfo fs.FileInfo, err error) error {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+
+		path := strings.TrimPrefix(localpath, instance.rootPath)
+		path = strings.TrimPrefix(path, "\\")
+		if localinfo.IsDir() {
+			return instance.fs.MkdirAll(path, 0777)
+		}
+		if strings.HasPrefix(path, ".") {
+			return nil
+		}
+
+		var localstate projfs.PRJ_FILE_STATE
+		hr := projfs.PrjGetOnDiskFileState(localpath, &localstate)
+		if hr != 0 {
+			return projfs.ErrorByCode(hr)
+		}
+
+		if (localstate | (projfs.PRJ_FILE_STATE_FULL & projfs.PRJ_FILE_STATE_HYDRATED_PLACEHOLDER)) != 0 {
+			// check if local is newer
+			remoteinfo, err := instance.fs.Stat(path)
+			if os.IsNotExist(err) {
+				// new local file, remote does not exist
+				log.Printf("Uploading file '%s'", path)
+				return instance.streamLocalToRemote(path)
+			}
+			if err != nil {
+				return err
+			}
+			// info from walk return modification time of 2185 TODO: why?
+			localinfo, err := os.Stat(localpath)
+			if err != nil {
+				return err
+			}
+			localmodtime := localinfo.ModTime()
+			localtime := localmodtime.Unix()
+			remotetime := remoteinfo.ModTime().Unix()
+			if localtime > remotetime {
+				log.Printf("Updating remote file '%s'", path)
+				return instance.streamLocalToRemote(path)
+			}
+		}
+		return nil
+	})
+}
+
 func (instance *VirtualizationInstance) getVirtualizationInfoFileName() string {
 	return instance.rootPath + "\\.virtualization"
 }
@@ -174,8 +244,13 @@ func (instance *VirtualizationInstance) get_callbacks() *projfs.PRJ_CALLBACKS {
 	}
 }
 
-func (instance *VirtualizationInstance) UpdateFileIfNeeded(relativePath string, placeholderInfo *projfs.PRJ_PLACEHOLDER_INFO, length uint32, updateFlags projfs.PRJ_UPDATE_TYPES, failureReason *projfs.PRJ_UPDATE_FAILURE_CAUSES) error {
-	return projfs.ErrorByCode(projfs.PrjUpdateFileIfNeeded(instance._instanceHandle, relativePath, placeholderInfo, length, updateFlags, failureReason))
+func (instance *VirtualizationInstance) UpdateFileIfNeeded(relativePath string, placeholderInfo *projfs.PRJ_PLACEHOLDER_INFO, length uint32, updateFlags projfs.PRJ_UPDATE_TYPES) error {
+	var failureReason projfs.PRJ_UPDATE_FAILURE_CAUSES
+	err := projfs.ErrorByCode(projfs.PrjUpdateFileIfNeeded(instance._instanceHandle, relativePath, placeholderInfo, length, updateFlags, &failureReason))
+	if err != nil {
+		err = fmt.Errorf("UpdateFileIfNeeded failed: %w (reason: %d)", err, failureReason)
+	}
+	return err
 }
 
 func returncode(err error) uintptr {
@@ -204,11 +279,7 @@ func (instance *VirtualizationInstance) Notify(callbackData *projfs.PRJ_CALLBACK
 		}
 	case projfs.PRJ_NOTIFICATION_FILE_HANDLE_CLOSED_FILE_MODIFIED, projfs.PRJ_NOTIFICATION_FILE_OVERWRITTEN:
 		if !IsDirectory {
-			data, err := os.ReadFile(instance.rootPath + "\\" + filename)
-			if err != nil {
-				return returncode(err)
-			}
-			return returncode(afero.WriteFile(instance.fs, filename, data, 0666))
+			return returncode(instance.streamLocalToRemote(filename))
 		}
 	case projfs.PRJ_NOTIFICATION_FILE_HANDLE_CLOSED_FILE_DELETED:
 		return returncode(instance.fs.Remove(filename))
@@ -216,6 +287,14 @@ func (instance *VirtualizationInstance) Notify(callbackData *projfs.PRJ_CALLBACK
 	return 0
 }
 
+func (instance *VirtualizationInstance) streamLocalToRemote(filename string) error {
+	data, err := os.ReadFile(instance.rootPath + "\\" + filename)
+	if err != nil {
+		return err
+	}
+	return afero.WriteFile(instance.fs, filename, data, 0666)
+}
+
 func (instance *VirtualizationInstance) QueryFileName(callbackData *projfs.PRJ_CALLBACK_DATA) uintptr {
 	log.Printf("QueryFileName: '%s'", callbackData.GetFilePathName())
 	return 0
@@ -287,17 +366,35 @@ func (instance *VirtualizationInstance) GetDirectoryEnumeration(callbackData *pr
 }
 
 func toBasicInfo(file fs.FileInfo) projfs.PRJ_FILE_BASIC_INFO {
+	ftime := syscall.NsecToFiletime(file.ModTime().UnixNano())
 	return projfs.PRJ_FILE_BASIC_INFO{
 		IsDirectory:    file.IsDir(),
 		FileSize:       file.Size(),
-		CreationTime:   file.ModTime().Unix(),
-		LastAccessTime: file.ModTime().Unix(),
-		LastWriteTime:  file.ModTime().Unix(),
-		ChangeTime:     file.ModTime().Unix(),
+		CreationTime:   ftime,
+		LastAccessTime: ftime,
+		LastWriteTime:  ftime,
+		ChangeTime:     ftime,
 		FileAttributes: 0,
 	}
 }
 
+func getVersionInfo(basicInfo *projfs.PRJ_FILE_BASIC_INFO) projfs.PRJ_PLACEHOLDER_VERSION_INFO {
+	result := projfs.PRJ_PLACEHOLDER_VERSION_INFO{
+		ProviderID: [projfs.PRJ_PLACEHOLDER_ID_LENGTH]byte{0, 0x1},
+		ContentID:  [projfs.PRJ_PLACEHOLDER_ID_LENGTH]byte{0},
+	}
+
+	version := uint64(basicInfo.LastWriteTime.Nanoseconds())
+	binary.LittleEndian.PutUint64(result.ContentID[:], version)
+	log.Printf("Version: %d %v", version, result.ContentID)
+	return result
+}
+
+func FillInPlaceholderInfo(data *projfs.PRJ_PLACEHOLDER_INFO, fileinfo fs.FileInfo) {
+	data.FileBasicInfo = toBasicInfo(fileinfo)
+	data.VersionInfo = getVersionInfo(&data.FileBasicInfo)
+}
+
 func (instance *VirtualizationInstance) GetPlaceholderInfo(callbackData *projfs.PRJ_CALLBACK_DATA) uintptr {
 	var data projfs.PRJ_PLACEHOLDER_INFO
 	filename := callbackData.GetFilePathName()
@@ -310,7 +407,7 @@ func (instance *VirtualizationInstance) GetPlaceholderInfo(callbackData *projfs.
 		log.Printf("Error getting placeholder info for %s: %s", filename, err)
 		return uintptr(syscall.EIO)
 	}
-	data.FileBasicInfo = toBasicInfo(stat)
+	FillInPlaceholderInfo(&data, stat)
 	return projfs.PrjWritePlaceholderInfo(instance._instanceHandle, callbackData.GetFilePathName(), &data, uint32(unsafe.Sizeof(data)))
 }
 
diff --git a/filesystem_test.go b/filesystem_test.go
index 6da0b3e..1e01a52 100644
--- a/filesystem_test.go
+++ b/filesystem_test.go
@@ -2,13 +2,13 @@ package projfero_test
 
 import (
 	"bytes"
-	"io"
 	"log"
 	"os"
 	"os/exec"
 	"reflect"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/balazsgrill/projfero"
 	"github.com/spf13/afero"
@@ -18,7 +18,7 @@ type testInstance struct {
 	t         *testing.T
 	location  string
 	fs        afero.Fs
-	closer    io.Closer
+	closer    projfero.Virtualization
 	closechan chan bool
 }
 
@@ -295,12 +295,19 @@ func TestChangedOnBackend(t *testing.T) {
 		t.Errorf("expected %v, got %v", data, data2)
 	}
 
+	// sleep for a bit to ensure that the file timestamp is different
+	time.Sleep(time.Second)
 	data = []byte("somethingelse")
 	err = afero.WriteFile(instance.fs, filename, data, 0x777)
 	if err != nil {
 		t.Fatal(err)
 	}
 
+	err = instance.closer.PerformSynchronization()
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	data2, err = os.ReadFile(instance.location + "\\" + filename)
 	if err != nil {
 		t.Fatal(err)
@@ -350,6 +357,7 @@ func TestUpdatedLocallyWhileOffline(t *testing.T) {
 	}
 
 	instance.stop()
+	time.Sleep(time.Second)
 
 	data = []byte("somethingelse")
 	err = instance.osWriteFile(filename, string(data))
@@ -358,13 +366,17 @@ func TestUpdatedLocallyWhileOffline(t *testing.T) {
 	}
 
 	instance.start()
+	err = instance.closer.PerformSynchronization()
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	data2, err := afero.ReadFile(instance.fs, filename)
 	if err != nil {
 		t.Fatal(err)
 	}
-	if !bytes.Equal(data, data2) {
-		t.Errorf("expected %s, got %s", string(data), string(data2))
+	if string(data) != strings.TrimSpace(string(data2)) {
+		t.Errorf("expected '%s', got '%s'", string(data), string(data2))
 	}
 	instance.stop()
 }
diff --git a/go.mod b/go.mod
index c5fd4cf..a6f47e2 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module github.com/balazsgrill/projfero
 go 1.21.0
 
 require (
-	github.com/balazsgrill/projfs v0.0.1
+	github.com/balazsgrill/projfs v0.0.2
 	github.com/google/uuid v1.6.0
 	github.com/spf13/afero v1.11.0
 )
diff --git a/go.sum b/go.sum
index eb10ac3..6572fb7 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-github.com/balazsgrill/projfs v0.0.1 h1:ot7RKyspqAfLdr3QZjLZzhS6m0lcxp/VPrRELhZNh0U=
-github.com/balazsgrill/projfs v0.0.1/go.mod h1:zxk3JTKjlt3AKYJ98gJQEpJ6ZQ+qtkyuqsgfMLb5mW4=
+github.com/balazsgrill/projfs v0.0.2 h1:HyhDgJT1sgIdHd1j1OHr/YYeDauQINzd+irerpaBlUM=
+github.com/balazsgrill/projfs v0.0.2/go.mod h1:zxk3JTKjlt3AKYJ98gJQEpJ6ZQ+qtkyuqsgfMLb5mW4=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/spf13/afero v1.11.0 h1:WJQKhtpdm3v2IzqG8VMqrr6Rf3UYpEF239Jy9wNepM8=