My last job paid me for 4 hours for the call in even it only took 15 minutes to fix the problem.
You may get called in and yes, it can be annoying at times but you get well compensated for it.
I once earned a week of vacation time in a month when we were installing a new time system.
Of course now days the boss calls me in at all times of the day or night when there is a problem and the cheapskate doesn't even give me a cup of coffee. Such are the joys of being the owner.