Does postgres user on linux need login permission?

[prakhar jauhari <prak840@xxxxxxxxx>]

Hey,

I am using postgres9.2, on a linux 6.3 box.

For start i created a user postgres on linux with login permission and no password.

Is it necessary for the postgres user to have login permissions?

Can i change it to "no login" with out breaking basebackup and Streaming Replication from other machines.?