I saw them open for Ozzy 2 decades ago.

Yeah with Slipknot.

Are you going into the pit? If so, here's a list of useful tips: [spoiler] Bring lots of water, last thing you want is to pass out from dehydration in the pit If you see somebody on the ground, try to help them up You are more than likely to be pushed around, don't get pissy with people for moshing in a moshpit If people are trying to get out, help them out of the pit Do NOT get caught in the middle of a wall of death Keep valuable belongings outside of the pit Please for the love of god don't be that one crowd killing dude If somebody isn't moshing, please respect that, and don't push them around And last but not least, have fun! [/spoiler]