diff --git a/weed/server/filer_grpc_server.go b/weed/server/filer_grpc_server.go
index ebb6021af..e8f026943 100644
--- a/weed/server/filer_grpc_server.go
+++ b/weed/server/filer_grpc_server.go
@@ -388,11 +388,7 @@ func (fs *FilerServer) DeleteEntry(ctx context.Context, req *filer_pb.DeleteEntr
 
 func (fs *FilerServer) AssignVolume(ctx context.Context, req *filer_pb.AssignVolumeRequest) (resp *filer_pb.AssignVolumeResponse, err error) {
 
-	if req.DiskType == "" {
-		req.DiskType = fs.option.DiskType
-	}
-
-	so, err := fs.detectStorageOption(ctx, req.Path, req.Collection, req.Replication, req.TtlSec, req.DiskType, req.DataCenter, req.Rack, req.DataNode)
+	so, err := fs.resolveAssignStorageOption(ctx, req)
 	if err != nil {
 		glog.V(3).InfofCtx(ctx, "AssignVolume: %v", err)
 		return &filer_pb.AssignVolumeResponse{Error: fmt.Sprintf("assign volume: %v", err)}, nil
@@ -424,6 +420,21 @@ func (fs *FilerServer) AssignVolume(ctx context.Context, req *filer_pb.AssignVol
 	}, nil
 }
 
+func (fs *FilerServer) resolveAssignStorageOption(ctx context.Context, req *filer_pb.AssignVolumeRequest) (*operation.StorageOption, error) {
+	so, err := fs.detectStorageOption(ctx, req.Path, req.Collection, req.Replication, req.TtlSec, req.DiskType, req.DataCenter, req.Rack, req.DataNode)
+	if err != nil {
+		return nil, err
+	}
+
+	// Mirror the HTTP write path: only apply the filer's default disk when the
+	// matched locationPrefix rule did not already select one.
+	if so.DiskType == "" {
+		so.DiskType = fs.option.DiskType
+	}
+
+	return so, nil
+}
+
 func (fs *FilerServer) CollectionList(ctx context.Context, req *filer_pb.CollectionListRequest) (resp *filer_pb.CollectionListResponse, err error) {
 
 	glog.V(4).InfofCtx(ctx, "CollectionList %v", req)
diff --git a/weed/server/filer_grpc_server_test.go b/weed/server/filer_grpc_server_test.go
new file mode 100644
index 000000000..31a83a541
--- /dev/null
+++ b/weed/server/filer_grpc_server_test.go
@@ -0,0 +1,68 @@
+package weed_server
+
+import (
+	"context"
+	"testing"
+
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+)
+
+func TestResolveAssignStorageOptionUsesBucketRuleBeforeFilerDiskDefault(t *testing.T) {
+	fc := filer.NewFilerConf()
+	if err := fc.SetLocationConf(&filer_pb.FilerConf_PathConf{
+		LocationPrefix: "/buckets/zot",
+		DiskType:       "disk",
+	}); err != nil {
+		t.Fatalf("set location conf: %v", err)
+	}
+
+	fs := &FilerServer{
+		option: &FilerOption{
+			DiskType: "hdd",
+		},
+		filer: &filer.Filer{
+			DirBucketsPath:    "/buckets",
+			FilerConf:         fc,
+			MaxFilenameLength: 255,
+		},
+	}
+
+	so, err := fs.resolveAssignStorageOption(context.Background(), &filer_pb.AssignVolumeRequest{
+		Path: "/buckets/zot/.uploads/upload-id/0001_part.part",
+	})
+	if err != nil {
+		t.Fatalf("resolve assign storage option: %v", err)
+	}
+
+	if got, want := so.Collection, "zot"; got != want {
+		t.Fatalf("collection = %q, want %q", got, want)
+	}
+	if got, want := so.DiskType, "disk"; got != want {
+		t.Fatalf("disk type = %q, want %q", got, want)
+	}
+}
+
+func TestResolveAssignStorageOptionFallsBackToFilerDiskDefault(t *testing.T) {
+	fs := &FilerServer{
+		option: &FilerOption{
+			DiskType: "hdd",
+		},
+		filer: &filer.Filer{
+			DirBucketsPath:    "/buckets",
+			FilerConf:         filer.NewFilerConf(),
+			MaxFilenameLength: 255,
+		},
+	}
+
+	so, err := fs.resolveAssignStorageOption(context.Background(), &filer_pb.AssignVolumeRequest{
+		Path: "/tmp/unmatched/file.bin",
+	})
+	if err != nil {
+		t.Fatalf("resolve assign storage option: %v", err)
+	}
+
+	if got, want := so.DiskType, "hdd"; got != want {
+		t.Fatalf("disk type = %q, want %q", got, want)
+	}
+}
diff --git a/weed/server/filer_server_tus_handlers.go b/weed/server/filer_server_tus_handlers.go
index 765040182..3afa1b6af 100644
--- a/weed/server/filer_server_tus_handlers.go
+++ b/weed/server/filer_server_tus_handlers.go
@@ -321,6 +321,11 @@ func (fs *FilerServer) tusWriteData(ctx context.Context, session *TusSession, of
 		return 0, fmt.Errorf("detect storage option: %w", err)
 	}
 
+	// When DiskType is empty, use filer's -disk
+	if so.DiskType == "" {
+		so.DiskType = fs.option.DiskType
+	}
+
 	// Read first bytes for MIME type detection
 	sniffSize := int64(512)
 	if contentLength < sniffSize {