Disk Utility - Resize Partition

Hmmm, not sure what you did to get what you have, but you cannot enlarge the bottom partition. You can only enlarge the top partition. My suggestion:

Delete that bottom partition. Drag the sizing gadget on the top partition all the way to the bottom. Click on the Apply button. When this is finished click in the resulting single partition then click on the Add [-] button which should automatically divide into two equally sized partitions. Click on the Apply button.

Now, this will erase whatever is on the lower partition you now have, but not the upper partition on which you have OS X installed. Be sure you have backups of your data before proceeding as a precaution.

To avoid having to do as Kappy suggests each time you decide you got the sizes wrong the last time, I recommend not partitioning the drive at all — just leave it as a single volume. There is rarely any very good reason to partition the everyday startup drive of a Mac. It just complicates backing up and causes you to bump repeatedly into storage limits that you've needlessly imposed on yourself.

This may be, but if the OP is looking to install different versions of OS X on the drive, then partitioning is essential.

There is no other solution. You can expand the top partition to fill the existing empty space between the two, but you can not expand the bottom partition upwards. This is only possible when you are partition a drive for the first time or repartitioning the entire drive, and it's not a startup drive that's currently active.

If you are willing to spend money to purchase a third-party utility, iPartition 3.4.1 ($45.00,) it can accomplish what you want, but otherwise you cannot do it in Disk Utility.

Right you can't expand the bottom partition upwards. Never could, not really odd.

But you don't have to increase the size of the top partition first. Just deleting the bottom partition and then Recreating it using all the unalocated space will include the space you took away from the top partition.

That's true for those looking to install different OS versions. But the OP does mention "the one with the OS," so it seemed safe to assume the lower partition wasn't intended to be a startup volume in this case.

The OP doesn't want to delete the bottom partition if possible (which it is not) except to expand the top partition and have unequal sized partitions.

Doesn't matter if he is or isn't installing another version of OS X. He wants to parttition for whatever reason. That is his choice.

Although your statement if fine for you for the OP it isn't.

May be, but the OP has stuff on that partition and prefers not to delete it. Could be another OS or just data. In any case the only solution for the OP that doesn't involved deleting a partition is simply to expand the upper partition into the existing free space and end up with unequally sized partitions.

Kappy wrote:

The OP doesn't want to delete the bottom partition if possible (which it is not) except to expand the top partition and have unequal sized partitions.

Right I understand that but to my knowledge there is no way yo expand the bottom partition upwards without first deleting it.

Not sure if there is a 3rd party partitioning programs for Mac's like there is for Windows. With those in Windows you can move space around as you like. But even with them sometimes you have to delete one of the partitions to be able to move it into another.

There is - iPartition 3.4.1. But it costs $45.00. Or you can try to become an expert with Unix command line programming and risk losing everything unless you really know what you are doing. 🙂

Well, that is always going to be the case copying from one partition on the drive to another because one r/w head can only be at one place at a time. Slower than copying between drives. Repartitioning your drive won't change this issue, but putting everything on a single drive will.

EDIT:

BTW, if you don't currently have a backup plan then I would consider making one. There is only one sure protection against drive failure - separate backups. Backup regularly and often. Multiple backups are better than one.