diff --git a/pkg/storage/fs/posix/posix.go b/pkg/storage/fs/posix/posix.go
index ed807f9015..276ec1c8d9 100644
--- a/pkg/storage/fs/posix/posix.go
+++ b/pkg/storage/fs/posix/posix.go
@@ -58,7 +58,8 @@ func init() {
 type posixFS struct {
 	storage.FS
 
-	um usermapper.Mapper
+	tree *tree.Tree
+	um   usermapper.Mapper
 }
 
 // New returns an implementation to of the storage.FS interface that talk to
@@ -215,11 +216,17 @@ func New(o *options.Options, stream events.Stream, cache, historyCache *idcache.
 
 	mw := middleware.NewFS(dfs, hooks...)
 	fs.FS = mw
+	fs.tree = tp
 	fs.um = um
 
 	return fs, nil
 }
 
+// WarmupIDCache allows triggering a posix fs scan and id cache warmup manually.
+func (fs *posixFS) WarmupIDCache(root string, assimilate, onlyDirty bool) error {
+	return fs.tree.WarmupIDCache(root, assimilate, onlyDirty)
+}
+
 // ListUploadSessions returns the upload sessions matching the given filter
 func (fs *posixFS) ListUploadSessions(ctx context.Context, filter storage.UploadSessionFilter) ([]storage.UploadSession, error) {
 	return fs.FS.(storage.UploadSessionLister).ListUploadSessions(ctx, filter)