In case you are wondering why I'm posting this question here at POTN rather than the Apple community forum. And answer is I get quicker response here 
THE BACKGROUND:
I bought a 2TB ext GoFlex drive when I got my iMac last September. I've partitioned it so that 1TB is strictly for the TimeMachine use only and the other 1TB as a for data use. As time passed. I've ignored the golden rule of "if it ain't broke, don't fix it". Since my main drive is sitting at 700+GB availability plus another 1TB on the data ext drive. And on top of that, all the "empty space" on the TimeMachine. I've decided to make a copies of my archived photos. Let's just say 550+GB I cannot remember the exact amount.
THE PROBLEM:
When the TimeMachine started to perform it's scheduled back up. It died due to lack of space. It even deleted (as it should) all the old backup files. I reverted to deleting the archived photos to create more room the next time TimeMachine performs it's duty. This action restored TimeMachine to normal operation. But I've noticed that the capacity on the TimeMachine partition is still high.
Available: 296.42 GB of 999.52 GB
THE PROPOSED SOLUTION:
Clean the TimeMachine partition by reformatting it. Then turn on TimeMachine. By the way, the archived photos are already stored in two different locations therefore the need for the third is anything but redundant/overkill.
This is when you tell me "if it ain't broke, don't fix it!!!!!!!"
