Is there any way to partition the SSD portion of a Fusion Drive?

Question

I'm looking at my next computer and am debating on whether or not to invest in a Fusion Drive. I'll be using Windows heavily on it though, and would like to take advantage of the SSD on both operating systems rather than just from within OS X.

I'm pretty technically savvy, so I wouldn't mind using Windows, Linux or another operating system to accomplish this task.

Thanks!

Answer 1

Since FusionDrive is really Corestorage with some added magic (or supposed to), there is no mandatory reason to assign the whole SSD to the Fusion drive.

When creating you DIY Fusion drive, just reserve space by creating adequate partitions and refer to the partition ID (diskXsY) instead of the whole disk.

Answer 2

In my opinion it shouldn't be a problem:

1. delete the CoreStorage LVG (FusionDrive) and end with 2 seperate disks: the SSD and the HDD.

2. Install Mac OS X on the SSD.

3. use the Bootcamp Camp Assistant to install Windows 7/8 on the SSD

4. partition the HDD according to your needs (HFS+ & NTFS/HFS+/NTFS)

You will end with a partition layout similar to that:

/dev/disk0 (SSD)
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *100.2 GB   disk0
   1:                        EFI                         209.7 MB   disk0s1
   2:                  Apple_HFS MacSystem                49.6 GB   disk0s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3
   4:                     MS-DOS WinSystem                49.6 GB   disk0s4            
/dev/disk1 (HDD)
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *3.0 TB     disk1
   1:                        EFI                       209.7 MB     disk1s1
   2:                  Apple_HFS MacData                 1,5 TB     disk1s2
   3:                     MS-DOS WinData                 1,5 TB     disk1s3

Caveats:

• both systems have to be installed on the size restricted SSD

• the data partition i/o won't benefit from the SSD

There is no way that both systems will benefit from a FusionDrive in the sense of fast I/O and size.

Answer 3

Fusion Drive technology is part of the Mac OS itself. Windows cannot use it.

It can, of course see the Core Storage Drive & its NTFS partition & boot from it, but it cannot use the hybrid technology underlying 'Fusion' itself.

Bootcamp will make the NTFS partition purely on the HD.

btw, Bootcamp is the only way to add the extra partition to a Fusion Drive. Anything else will break it, requiring you to totally rebuild the structure from scratch using Terminal.
Disk Utility cannot remake or properly readjust a Core Storage Volume.
Don't touch the partition itself from inside Windows.

Answer 4

Yes. Note that the fusion Drive is a HD drive with a small SSD apart (look for replace fusion drive), running in RAID

Will ned to run the Mac OS in a SD card or flash drive.

1. Discover the IDENTIFIER of each one on terminal type: diskutil list

2. Erase (format) each one in my case (disk0 and disk1), I was using a SD card as my HD (I installed the OS in a SD card), you can not make that running the Mac from it's internal fusion drive. In terminal:

   diskutil eraseDisk JHFS+ HD disk1
   

   and

   diskutil eraseDisk JHFS+ SSD disk0
   

Now you can use Disk Utility to rename, create partition, etc

(I figured it out 'damaging' my fusion drive trying to partition it)