diff --git a/cmd/zrok/copyFrom.go b/cmd/zrok/copyFrom.go
index c211a2c3..8b4e78b3 100644
--- a/cmd/zrok/copyFrom.go
+++ b/cmd/zrok/copyFrom.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"github.com/openziti/zrok/util/sync"
-	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 )
 
@@ -31,18 +30,10 @@ func (cmd *copyFromCommand) run(_ *cobra.Command, args []string) {
 		target = args[1]
 	}
 
-	t := sync.NewFilesystemTarget(&sync.FilesystemTargetConfig{
+	dst := sync.NewFilesystemTarget(&sync.FilesystemTargetConfig{
 		Root: target,
 	})
-	destTree, err := t.Inventory()
-	if err != nil {
-		panic(err)
-	}
-	for _, f := range destTree {
-		logrus.Infof("<- %v [%v, %v, %v]", f.Path, f.Size, f.Modified, f.ETag)
-	}
-
-	s, err := sync.NewWebDAVTarget(&sync.WebDAVTargetConfig{
+	src, err := sync.NewWebDAVTarget(&sync.WebDAVTargetConfig{
 		URL:      args[0],
 		Username: "",
 		Password: "",
@@ -50,11 +41,8 @@ func (cmd *copyFromCommand) run(_ *cobra.Command, args []string) {
 	if err != nil {
 		panic(err)
 	}
-	srcTree, err := s.Inventory()
-	if err != nil {
+
+	if err := sync.Synchronize(src, dst); err != nil {
 		panic(err)
 	}
-	for _, f := range srcTree {
-		logrus.Infof("-> %v [%v, %v, %v]", f.Path, f.Size, f.Modified, f.ETag)
-	}
 }
diff --git a/util/sync/synchronizer.go b/util/sync/synchronizer.go
new file mode 100644
index 00000000..ec168b4d
--- /dev/null
+++ b/util/sync/synchronizer.go
@@ -0,0 +1,41 @@
+package sync
+
+import (
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+func Synchronize(src, dst Target) error {
+	srcTree, err := src.Inventory()
+	if err != nil {
+		return errors.Wrap(err, "error creating source inventory")
+	}
+
+	dstTree, err := dst.Inventory()
+	if err != nil {
+		return errors.Wrap(err, "error creating destination inventory")
+	}
+
+	dstIndex := make(map[string]*Object)
+	for _, f := range dstTree {
+		dstIndex[f.Path] = f
+	}
+
+	var copyList []*Object
+	for _, srcF := range srcTree {
+		if dstF, found := dstIndex[srcF.Path]; found {
+			if dstF.ETag != srcF.ETag {
+				copyList = append(copyList, srcF)
+			}
+		} else {
+			copyList = append(copyList, srcF)
+		}
+	}
+
+	logrus.Infof("files to copy:")
+	for _, copy := range copyList {
+		logrus.Infof("-> %v", copy.Path)
+	}
+
+	return nil
+}