Varnishncsa log file size

[Admin Beckspaced]

Hello Varnish-Users,

recently I have setup varnish logging via varnishncsa.
If I look at the varnish log file size it's currently around 50 MB per 
day which gets rotate daily via logrotate.

How big can the log file size grow without any performance issues?
Is 100 MB still a valid log file size? even 500 MB perhaps?

The more domains I add the bigger the log file will grow per day. Any 
hints are welcome ;)

Thanks & greetings
Becki