I've had this problem for a while now. My linux server is set to wake-on-lan but occasionally it halts at Grubs "Starting Up..." and goes no further. This is not due to additional hardware being attached such as a flash drive or anything as I never plug anything into it. It may boot perfectly 40 times in a row and then hit this issue. Sometimes it gets the issue a couple of times in quick succession and doesn't happen for ages again. I'm not sure how to diagnose it since it doesn't seem to be reproducible. Any help much appreciated.
Well, it's been a while since I've had one of these, mainly because my server has been on for a long time. However, I've captured an instance and I have the dmesg file but due to its size I can't just paste it below. Looking at the file, there's a period between 3.164 seconds and 14.13 seconds where there are no messages. I'll look at hosting the file somewhere but in the meantime, are there any messages in particular that I should look for?