How to add a user to a group in Synology Network Attached Storage

A simple task for adding a certain user to a group in a NAS device. The device is made by Sinology Inc. It is a Taiwanese corporation specializes in Network-attached storage appliances. The device itself has its own operating system. According to the information in this link in Wikipedia, there is a detail for the information about it.  It states that Synology’s primary product is the Synology DiskStation Manager (DSM), a Linux based software package that is the operating system for the DiskStation and RackStation products. The Synology DSM is the foundation of the DiskStation, which integrates the basic functions of file sharing, centralized backup, RAID storage, multimedia streaming, virtual storage, and using the DiskStation as a network video recorder. Synology also provides free mobile applications for its users, including support for iOS, Android, Windows Phone, and Kindle Fire.

So, basically, the device has its own operating system. Furthermore, the operating system is a linux operating system. In that case, every single basic operation normally function in a normal linux operating system will run on it too. Including the command for adding a user to a group. Unfortunately, the command for achieving it is completely different. The following is the actual command in a normal linux operating system :

root@hostname:~# usermod user -G apache
root@hostname:~# id user
uid=1000(user) gid=1000(user) groups=1000(user),33(apache)
root@hostname:~#

On the other hand, the following is the actual command for adding a user to a group in the linux operating system located in synology device :

user@storage:~$ sudo synogroup --add admin user
Password: 
user@storage:~$ 
user@storage:~$ id user
uid=1027(user) gid=100(users) groups=100(users),65536(admin),101(administrators),0(root)
user@storage:~$ 

As shown in the above output, the command for adding a user with the name of ‘user’ into the group ‘admin’ is a success.