I'm not sure if TPS will drop when loading chunks takes a bit longer. It might.

As for fixing the issue, that won't take much time. If/when I have the funds it's just a matter of ordering a drive. Then pull the defective drive from the server and replace it with the new one. The raid controller will then start rebuilding the array automatically. After that is done I'll move the virtual machines back to the sas drives. All in all it won't take more than half an hour of button pushing. The rebuilding and virtual machine moving will take longer but that's just a progress bar filling up