private static void copyFile(File source, File dest) throws IOException {
        try (FileChannel sourceChannel = new FileInputStream(source).getChannel();
             FileChannel destChannel = new FileOutputStream(dest).getChannel()) {
            destChannel.transferFrom(sourceChannel, 0, sourceChannel.size());
        }
    }
Global file directory, holding files for file distribution for all deployed applications.
configserver/src/main/java/com/yahoo/vespa/config/server/filedistribution/FileDirectory.java