[Amresh]

Keep watch on your bandwidth, and maybe limit the bandwidth. Also use fail2ban to know which IP DDOS-ing you. It also drop any connection that DDOS you.
Also don't forget to use UFW or IPTables, that firewall is really good. Only open which port you like, ex 80 for web server, 9987 for TS3 voice, etc.

Then, how to know which IP DDOS-ing you?
https://post4vps.com/thread-205.html
Open that thread, and look step number 9.

Yes @tiwil , (D)Dos is the main problem!
Also, don't use any other game except SA-MP and MTA as they consume less RAM and bandwidth if less people are connected!

by the way @tiwil why don't you host your own game server on you vps as it has unlimited bandwidth and great RAM!
I have read your host TOS and they say that you can host a game server on your VPS!!
plz @tiwil make a samp server for our forum people to chill out there!