One frustrating aspect of Boot Camp is that it doesn’t support hard drives larger than 2.2TB. That means that if you custom install a larger hard drive, or order a new iMac with a 3TB hard drive, you won’t be able to use all of that space to run Windows. Luckily, there’s now a partial fix, thanks to the developer of Winclone.
The fix is detailed, but here’s the jist:
In order to make Windows bootable on a 3 TB (or larger) drive, the Windows partition must be the last of the first four, and be contained within the first 2.2 TB of the drive. Disk Utility makes this easy to do. Shrink the existing Macintosh HD partition, and create a DOS partition so that if you add up the first four partition, they will be less than 2.2 TB total. The EFI partition and recovery partition are small (together they are less than 1 GB). Do not partition right up to the 2.2 TB limit, but leave some space. A good rule of thumb is that the Mac and Windows partitions added together should be less than 2 TB total. Finally, create a Mac partition that uses the remaining space following the Windows partition. Note that this partition will not be accessbile by Windows, but OS X will be able to see and use this space. See the screen shot below for an example layout.
It doesn’t look hard, although you do need to use a very specific partitioning strategy to get results. Given the simplicity of this fix, however, let’s hope Apple patches Boot Camp to get around the 2.2TB limit sooner rather than later.
Did this work for you? Let us know in the comments.