diff --git a/agent/deep_assistant.py b/agent/deep_assistant.py
index 957b0d0..1cf54ad 100644
--- a/agent/deep_assistant.py
+++ b/agent/deep_assistant.py
@@ -478,13 +478,19 @@ def create_custom_cli_agent(
             backend = FilesystemBackend(root_dir=workspace_root, virtual_mode=False)
 
         # Set up composite backend with routing based on the new implementation
+        # NOTE: virtual_mode=True anchors all paths to root_dir. This is required for
+        # these offload-only backends: CompositeBackend strips the route prefix and
+        # forwards "/" to grep, so virtual_mode=False would resolve "/" to the real
+        # filesystem root and scan the whole disk (hitting /usr, /var, other sessions'
+        # temp dirs), causing 45-152s grep calls. virtual_mode=True confines grep to
+        # the temp dir and filters out-of-root results.
         large_results_backend = FilesystemBackend(
             root_dir=tempfile.mkdtemp(prefix="deepagents_large_results_"),
-            virtual_mode=False,
+            virtual_mode=True,
         )
         conversation_history_backend = FilesystemBackend(
             root_dir=tempfile.mkdtemp(prefix="deepagents_conversation_history_"),
-            virtual_mode=False,
+            virtual_mode=True,
         )
         composite_backend = CompositeBackend(
             default=backend,