diff --git a/components/engine/client/container_copy.go b/components/engine/client/container_copy.go
index 30ba6803f0..b7d5252ab2 100644
--- a/components/engine/client/container_copy.go
+++ b/components/engine/client/container_copy.go
@@ -30,7 +30,7 @@ func (cli *Client) ContainerStatPath(ctx context.Context, containerID, path stri
 }
 
 // CopyToContainer copies content into the container filesystem.
-// Note that `content` must be a Reader for a TAR
+// Note that `content` must be a Reader for a TAR archive
 func (cli *Client) CopyToContainer(ctx context.Context, container, path string, content io.Reader, options types.CopyToContainerOptions) error {
 	query := url.Values{}
 	query.Set("path", filepath.ToSlash(path)) // Normalize the paths used in the API.
@@ -59,7 +59,7 @@ func (cli *Client) CopyToContainer(ctx context.Context, container, path string,
 }
 
 // CopyFromContainer gets the content from the container and returns it as a Reader
-// to manipulate it in the host. It's up to the caller to close the reader.
+// for a TAR archive to manipulate it in the host. It's up to the caller to close the reader.
 func (cli *Client) CopyFromContainer(ctx context.Context, container, srcPath string) (io.ReadCloser, types.ContainerPathStat, error) {
 	query := make(url.Values, 1)
 	query.Set("path", filepath.ToSlash(srcPath)) // Normalize the paths used in the API.
diff --git a/components/engine/libcontainerd/client_daemon.go b/components/engine/libcontainerd/client_daemon.go
index 7508968fd5..79b5e478be 100644
--- a/components/engine/libcontainerd/client_daemon.go
+++ b/components/engine/libcontainerd/client_daemon.go
@@ -147,7 +147,7 @@ func (c *client) Restore(ctx context.Context, id string, attachStdio StdioCallba
 		rio, err = attachStdio(io)
 		return rio, err
 	})
-	if err != nil && !strings.Contains(err.Error(), "no running task found") {
+	if err != nil && !errdefs.IsNotFound(errors.Cause(err)) {
 		return false, -1, err
 	}
 
@@ -262,8 +262,9 @@ func (c *client) Start(ctx context.Context, id, checkpointDir string, withStdin
 		func(_ context.Context, _ *containerd.Client, info *containerd.TaskInfo) error {
 			info.Checkpoint = cp
 			info.Options = &runctypes.CreateOptions{
-				IoUid: uint32(uid),
-				IoGid: uint32(gid),
+				IoUid:       uint32(uid),
+				IoGid:       uint32(gid),
+				NoPivotRoot: os.Getenv("DOCKER_RAMDISK") != "",
 			}
 			return nil
 		})