[gitgud]

This is true, but alerts and monitoring software can fail in many ways, due to network issues, process crashes... Etc.

Due to the simplicity of this solution, there's not much that can go wrong.... unless you can't actually access the server anymore to delete the file...

I see this more as a second line of defence

[luckylion]

If the monitoring fails to alert you, you don't get the alert that you're running out of disk space and you can't access the server to delete the spacer file. All you've done in that case is lower your disk space by 8gb and make your server fill up more quickly.