Put Backdoor in Linux System?

I have been experimenting with metasploit and metasploitable lately, and on the meterpreter, the Persistence option seems to be only available for Windows. Is there any way to put a backdoor on a Linux machine from a shell or Meterpreter? And if not, what other ways could I do this?

(P.S. the target is Metasploitable)

Thanks,

Chris