diff --git a/src/api2/admin/datastore/backup.rs b/src/api2/admin/datastore/backup.rs
index 2255df15..06dcacc3 100644
--- a/src/api2/admin/datastore/backup.rs
+++ b/src/api2/admin/datastore/backup.rs
@@ -77,12 +77,12 @@ fn upgrade_to_backup_protocol(
     let last_backup = BackupInfo::last_backup(&datastore.base_path(), &backup_group)?;
     let backup_dir = BackupDir::new_with_group(backup_group, backup_time.timestamp());
 
-    let (path, is_new) = datastore.create_backup_dir(&backup_dir)?;
+    let (_path, is_new) = datastore.create_backup_dir(&backup_dir)?;
     if !is_new { bail!("backup directorty already exists."); }
 
     WorkerTask::spawn("backup", Some(worker_id), &username.clone(), true, move |worker| {
         let mut backup_env = BackupEnvironment::new(
-            env_type, username.clone(), worker.clone(), datastore, backup_dir, path);
+            env_type, username.clone(), worker.clone(), datastore, backup_dir);
 
         backup_env.last_backup = last_backup;
 
@@ -173,7 +173,7 @@ fn create_dynamic_index(
         archive_name.push_str(".didx");
     }
 
-    let mut path = env.path.clone();
+    let mut path = env.backup_dir.relative_path();
     path.push(archive_name);
 
     let chunk_size = 4096*1024; // todo: ??
diff --git a/src/api2/admin/datastore/backup/environment.rs b/src/api2/admin/datastore/backup/environment.rs
index 04c5a209..8f569aa7 100644
--- a/src/api2/admin/datastore/backup/environment.rs
+++ b/src/api2/admin/datastore/backup/environment.rs
@@ -1,7 +1,6 @@
 use failure::*;
 use std::sync::{Arc, Mutex};
 use std::collections::HashMap;
-use std::path::PathBuf;
 
 use serde_json::Value;
 
@@ -26,7 +25,6 @@ pub struct BackupEnvironment {
     pub worker: Arc<WorkerTask>,
     pub datastore: Arc<DataStore>,
     pub backup_dir: BackupDir,
-    pub path: PathBuf,
     pub last_backup: Option<BackupInfo>,
     state: Arc<Mutex<SharedBackupState>>
 }
@@ -38,7 +36,6 @@ impl BackupEnvironment {
         worker: Arc<WorkerTask>,
         datastore: Arc<DataStore>,
         backup_dir: BackupDir,
-        path: PathBuf,
     ) -> Self {
 
         let state = SharedBackupState {
@@ -54,7 +51,6 @@ impl BackupEnvironment {
             datastore,
             formatter: &JSON_FORMATTER,
             backup_dir,
-            path,
             last_backup: None,
             state: Arc::new(Mutex::new(state)),
         }