Pimcore\Model\Asset::deletePhysicalFile PHP Method

    protected function deletePhysicalFile()
    {
        $fsPath = $this->getFileSystemPath();
        if ($this->getType() != "folder") {
            if (is_file($fsPath) && is_writable($fsPath)) {
                unlink($fsPath);
            }
        } else {
            if (is_dir($fsPath) && is_writable($fsPath)) {
                recursiveDelete($fsPath, true);
            }
        }
    }