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480951

Cancelled
Original poster
Aug 14, 2010
639
914
I consider myself fairly experienced with Macs but when it comes to playing around with partitions (aside from Boot Camp) I'm not very knowledgeable. I made a 45GB partition for the Developer Build of Lion and find that it's never being used and would like to erase and merge it back with 10.6.7 so that the space its taken up is available.

Is there any way to do this without having to erase the entire drive? Every time I attempt it in Disk Utility it says the drive cannot be ejected (probably because it's the same one that SL is on). Any advice?
 

Mal

macrumors 603
Jan 6, 2002
6,252
18
Orlando
I consider myself fairly experienced with Macs but when it comes to playing around with partitions (aside from Boot Camp) I'm not very knowledgeable. I made a 45GB partition for the Developer Build of Lion and find that it's never being used and would like to erase and merge it back with 10.6.7 so that the space its taken up is available.

Is there any way to do this without having to erase the entire drive? Every time I attempt it in Disk Utility it says the drive cannot be ejected (probably because it's the same one that SL is on). Any advice?

While booted in Snow Leopard, open Disk Utility and go select the drive entry (the one that lists the physical drive, indicated by the size, which is probably the first entry in the list). Select the Partition tab, then select the Lion partition, which should be the second on the list. Click the - button at the bottom of that list, which will remove that partition (you'll have to wait for it to be erased). Then, drag the bottom right corner of your Snow Leopard partition down to fill the remainder of the space on the drive.

jW
 

480951

Cancelled
Original poster
Aug 14, 2010
639
914
Thanks for your explanation, it's very easy to follow and I now know what to do. After getting to the step of hitting the -, it says it will erase the partition, it gets to "Unmounting" then says "error, cannot unmount the disk". Why is it doing that?
 

roadbloc

macrumors G3
Aug 24, 2009
8,784
215
UK
Try a restart. If that doesn't work, try doing it from the Disk Utility on the Snow Leopard install disc instead.
 

480951

Cancelled
Original poster
Aug 14, 2010
639
914
A restart worked perfectly, thanks for your help. That space is now back on the main drive.
 
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