I have struggled with the log sizes getting too big and then the web pages refusing to list things on them (alerts/blocks pages show empty in UI). Clearing the logs manually instantly fixes the UI issue. I think the problem is the fact that logs can grow quite quickly and that relying on the log rotation can lead to a (very minimal) denial of service type event. I've thought about mucking with how often it rotates but as long as I'm not being legit DDOS'd it is just a nuisance. Suricata still clearly works. The firewall itself clearly works. The only real problem is UI issues when attempting to do a real investigation or troubleshoot. One can work around that manually. Of course somebody will simply say turn suricata off on the external interface. No. Occasionally good research happens there.