How To Extend A Partition In Disk Utility?

[JPM42]

I own an iMac with a 250 GB HDD along with a Macbook that originally had a 120 GB HDD. So when I purchased my 1 TB external HDD this summer, I partitioned the external so I could back up both my iMac and Macbook via Time Machine. Seeing how small the Macbook HDD was, I allocated roughly 300 GB of my external to it, with the iMac getting the rest.

Anyways, recently, I upgraded the Macbook's HDD to 500 GB and when I put in the new HDD, I just decided to start fresh and reinstall OS X and put back in necessary files. Anyways, ever since I've done this (and have added more space), Time Machine now says my drive is full and can no longer back up my Macbook.

Because of this, I wanted to change the partition, to make it a bit more even. However, while I'm able to drag the iMac's partition up or down, I'm not able to do that with the MB partition. I'm only able to shrink the partition, which I obviously don't want to do. Here's a screen capture of how it looks:

As you can see, I've shrunk the iMac's partition to accommodate the change, but my Macbook won't cooperate, hence the gap in between.

If there's any way for me to extend the space on my Macbook partition and get this fixed, that would be great.

Thanks!

 

[Hellhammer]

What if you click apply after you have shrunk the iMac partition? Maybe that will make it possible to extend the MB partition

 

[mulo]

why have a partition for each machine in the first place? - just delete the the MB partition and extend the imac partition, then set them both to backup onto that partition.
the backups wont conflict.

oh and you cant move or change the header on a partition, only the foot. So you will have to delete the macbook partition anyway, even if you just want it larger.

well truth be told there are utilities out there that will do it but i wouldn't recommend it.
i tried that on my 2TB drive and ended up having to completely reformat it.

 

[JPM42]

What if you click apply after you have shrunk the iMac partition? Maybe that will make it possible to extend the MB partition

Tried it with no success!

 

[JPM42]

why have a partition for each machine in the first place? - just delete the the MB partition and extend the imac partition, then set them both to backup onto that partition.
the backups wont conflict.

oh and you cant move or change the header on a partition, only the foot. So you will have to delete the macbook partition anyway, even if you just want it larger.

well truth be told there are utilities out there that will do it but i wouldn't recommend it.
i tried that on my 2TB drive and ended up having to completely reformat it.

The reason I had two partitions was so I'd be able to make two bootable clones through Carbon Copy Cloner.

I also heard about Time Machine being able to make two different backups without a partition, and without them being mixed up, but I heard that this wouldn't work if the computer has the same name. Is this true?

Thanks!