Yes. If I didn't feel that I can trust it, I would get another solution.
> You've never had a server fill up before you can respond to the alert?
I have. With the proposed hack in this article: it would fill up even faster: by that amount of time it would take the problem to write 8gb of data.
> Because believe me, they WILL go awry.
In my experience: not in any way that this would help. If your disk fills up, it's either slow (and your monitoring alerts you days or at least hours before it's a problem) or it's really, really fast. In the latter case, it's much faster than you can jump on your computer, ssh into the machine and delete your spacer file.
Invest in better monitoring, that's much, much, much, much better than adding spacer files to fill up your disk or changing the wall clock to give you more time.
If you've had a disk go full on you, what's the first thing you do? For me, I log in and start looking for a log file to truncate to buy me a few megs of space, at least. This spacer file is just a guaranteed way to find the space you need without having to hunt for it.
Also it doesn't HAVE to be 8GB. On most systems I think a 500mb file would be every bit as effective.
This 8gb file idea isn't to replace monitoring. It's to offer a quick stopgap solution so you can do things in a hurry and give yourself a little extra "out" when things go awry. Because believe me, they WILL go awry. And if you're not prepared for that eventuality, then I don't know what else to say.