External HDD problem with iMac OSX I purchased a 3TB HDD, which I put into an USB enclosure for my iMac.  The drive is recognized at boot, but it only shows 801.23GB. 

I formatted the drive with into two 1.5TB FAT32 partitions via Win7. My Windows machine shows the correct partitions, but when I attach the enclosure to my iMac it shows one 801.23GB partition.

Do you have any idea?
I have no idea why the Mac can't see the 2 partitions.

Try using Disk Utility on the Mac to format the drive with FAT 32, then give it 2 partitions, and see if the Windows likes it.

That's the best I can come up with.  It works with thumb drives.