diff --git a/src/bin/backup-client.rs b/src/bin/backup-client.rs
index 0931b937..47b730bd 100644
--- a/src/bin/backup-client.rs
+++ b/src/bin/backup-client.rs
@@ -10,6 +10,7 @@ use proxmox_backup::api::router::*;
 //use proxmox_backup::backup::chunk_store::*;
 //use proxmox_backup::backup::image_index::*;
 //use proxmox_backup::config::datastore;
+use proxmox_backup::catar::encoder::*;
 use proxmox_backup::backup::datastore::*;
 use serde_json::{Value};
 
@@ -17,7 +18,13 @@ fn required_string_param<'a>(param: &'a Value, name: &str) -> &'a str {
     param[name].as_str().expect(&format!("missing parameter '{}'", name))
 }
 
-fn backup_dir(datastore: &DataStore, file: &std::fs::File, target: &str, chunk_size: usize) -> Result<(), Error> {
+fn backup_dir(
+    datastore: &DataStore,
+    path: &str,
+    dir: &mut nix::dir::Dir,
+    target: &str,
+    chunk_size: usize,
+) -> Result<(), Error> {
 
     let mut target = std::path::PathBuf::from(target);
 
@@ -29,7 +36,12 @@ fn backup_dir(datastore: &DataStore, file: &std::fs::File, target: &str, chunk_s
         target.set_extension("aidx");
     }
 
-    bail!("not implemented");
+    // fixme: implement chunked writer
+    let writer = std::fs::File::create("mytest.catar")?;
+
+    let path = std::path::PathBuf::from(path);
+
+    CaTarEncoder::encode(path, dir, writer)?;
 
     Ok(())
 }
@@ -79,12 +91,15 @@ fn create_backup(param: Value, _info: &ApiMethod) -> Result<Value, Error> {
     let datastore = DataStore::open(store)?;
 
     let file = std::fs::File::open(filename)?;
-    let stat = nix::sys::stat::fstat(file.as_raw_fd())?;
+    let rawfd = file.as_raw_fd();
+    let stat = nix::sys::stat::fstat(rawfd)?;
 
     if (stat.st_mode & libc::S_IFDIR) != 0 {
         println!("Backup directory '{}' to '{}'", filename, store);
 
-        backup_dir(&datastore, &file, &target, chunk_size)?;
+        let mut dir = nix::dir::Dir::from_fd(rawfd)?;
+
+        backup_dir(&datastore, &filename, &mut dir, &target, chunk_size)?;
 
     } else if (stat.st_mode & (libc::S_IFREG|libc::S_IFBLK)) != 0 {
         println!("Backup file '{}' to '{}'", filename, store);
diff --git a/src/catar/encoder.rs b/src/catar/encoder.rs
new file mode 100644
index 00000000..b48d7049
--- /dev/null
+++ b/src/catar/encoder.rs
@@ -0,0 +1,82 @@
+use failure::*;
+
+use super::format_definition::*;
+
+use std::io::Write;
+use std::os::unix::io::AsRawFd;
+use std::os::unix::ffi::OsStrExt;
+
+pub struct CaTarEncoder<W: Write> {
+    current_path: std::path::PathBuf, // used for error reporting
+    writer: W,
+    size: usize,
+}
+
+impl <W: Write> CaTarEncoder<W> {
+
+    pub fn encode(mut path: std::path::PathBuf, dir: &mut nix::dir::Dir, writer: W) -> Result<(), Error> {
+        let mut me = Self {
+            current_path: path,
+            writer: writer,
+            size: 0,
+        };
+
+        // todo: use scandirat??
+
+        me.encode_dir(dir)?;
+
+        Ok(())
+    }
+
+    fn encode_dir(&mut self, dir: &mut nix::dir::Dir)  -> Result<(), Error> {
+
+        println!("encode_dir: {:?}", self.current_path);
+
+        let mut name_list = vec![];
+
+        let rawfd = dir.as_raw_fd();
+
+        let dir_stat = match nix::sys::stat::fstat(rawfd) {
+            Ok(stat) => stat,
+            Err(err) => bail!("fstat failed - {}", err),
+        };
+
+        for entry in dir.iter() {
+            let entry = match entry {
+                Ok(entry) => entry,
+                Err(err) => bail!("readir failed - {}", err),
+            };
+            let mut filename = entry.file_name().to_owned();
+
+            let name = filename.to_bytes_with_nul();
+            let name_len = name.len();
+            if name_len == 2 && name[0] == b'.' && name[1] == 0u8 { continue; }
+            if name_len == 3 && name[0] == b'.' && name[1] == b'.' && name[2] == 0u8 { continue; }
+
+            if let Ok(stat) = nix::sys::stat::fstatat(rawfd, filename.as_ref(), nix::fcntl::AtFlags::AT_SYMLINK_NOFOLLOW) {
+                //println!("Found {:?}", filename);
+                name_list.push((filename, stat));
+            } else {
+                bail!("fsstat failed");
+            }
+        }
+
+        name_list.sort_unstable_by(|a, b| a.0.cmp(&b.0));
+
+        for (filename, stat) in name_list {
+            //println!("SORTED {:?}", filename);
+
+            if (stat.st_mode & libc::S_IFDIR) != 0 {
+
+                let mut dir = nix::dir::Dir::openat(
+                    rawfd, filename.as_ref(), nix::fcntl::OFlag::O_NOFOLLOW, nix::sys::stat::Mode::empty())?;
+
+                self.current_path.push(std::ffi::OsStr::from_bytes(filename.as_bytes()));
+                self.encode_dir(&mut dir)?;
+                self.current_path.pop();
+            }
+        }
+
+        Ok(())
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 0d9ea664..f7e43b50 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -33,6 +33,7 @@ pub mod server {
 pub mod catar {
 
     pub mod format_definition;
+    pub mod encoder;
 }
 
 pub mod section_config;