Sean Gallardy wins the jackpot:
If, somehow, you’ve managed to see this error in your errorlog then congratulations, you’ve won an instance of SQL Server that probably won’t be doing much.
I found out about this message a few months ago, but it has been in the product for years and I went this long without ever even knowing it existed (congrats me!) until I was asked about it and coincidentally ended up finding it in an errorlog the same week. Clearly, I have too much fun packed into my weeks. I asked around, only one other person had ever found this in an errorlog before… that’s either impressive, depressing, or some perfect quantity of both – mellow it out to a smooth melancholy.
Click through to see more information about the 1000000 IO error message and when you might find it.