Retina iMac 3tb Fusion drive Boot Camp failure

Question

Trying to install Windows 8.1 to a 1tb Bootcamp partition on 3tb Fusion drive. BCA creates the partition, Windows installer sees it, but requires formatting it, but then it can&#x27;t install to it. I get an error that it can&#x27;t create or see the partition. I&#x27;m assuming this has to do with BCA creating the partition someplace Windows can&#x27;t handle it (past the first 2.2tb of the drive).Here is the info requested in a previous thread.Rogers-iMac:~ reberhart$ diskutil list/dev/disk0   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *121.3 GB   disk0   1:                        EFI EFI                     209.7 MB   disk0s1   2:          Apple_CoreStorage                         121.0 GB   disk0s2   3:                 Apple_Boot Boot OS X               134.2 MB   disk0s3/dev/disk1   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *3.0 TB     disk1   1:                        EFI EFI                     209.7 MB   disk1s1   2:          Apple_CoreStorage                         2.0 TB     disk1s2   3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3   4:       Microsoft Basic Data                         1.0 TB     disk1s4/dev/disk2   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:                  Apple_HFS Macintosh HD           *2.1 TB     disk2                                 Logical Volume on disk0s2, disk1s2                                 718A36B4-10B9-49A9-B585-CFC222080507                                 Unencrypted Fusion Drive/dev/disk3   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:     FDisk_partition_scheme                        *8.0 GB     disk3   1:                 DOS_FAT_32 WININSTALL              8.0 GB     disk3s1/dev/disk4   #:                       TYPE NAME                    SIZE       IDENTIFIER   0:      GUID_partition_scheme                        *4.0 TB     disk4   1:                        EFI EFI                     314.6 MB   disk4s1   2:                  Apple_HFS My Book                 4.0 TB     disk4s2Rogers-iMac:~ reberhart$ diskutil cs listCoreStorage logical volume groups (1 found)|+-- Logical Volume Group 49E959A5-5F3C-4178-8A2D-067D2C853A96    &#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;&#x3D;    Name:         Macintosh HD    Status:       Online    Size:         2118855286784 B (2.1 TB)    Free Space:   114688 B (114.7 KB)    |    +-&lt; Physical Volume D9052F80-9907-4815-8AF1-C9FF8D9C3293    |   ----------------------------------------------------    |   Index:    0    |   Disk:     disk0s2    |   Status:   Online    |   Size:     120988852224 B (121.0 GB)    |    +-&lt; Physical Volume E2271529-B42D-49F9-B231-3CAE6A0FF812    |   ----------------------------------------------------    |   Index:    1    |   Disk:     disk1s2    |   Status:   Online    |   Size:     1997866434560 B (2.0 TB)    |    +-&gt; Logical Volume Family AAC1C060-264E-4435-9992-5380CAF17B07        ----------------------------------------------------------        Encryption Status:       Unlocked        Encryption Type:         None        Conversion Status:       NoConversion        Conversion Direction:    -none-        Has Encrypted Extents:   No        Fully Secure:            No        Passphrase Required:     No        |        +-&gt; Logical Volume 718A36B4-10B9-49A9-B585-CFC222080507            ---------------------------------------------------            Disk:                  disk2            Status:                Online            Size (Total):          2112999915520 B (2.1 TB)            Conversion Progress:   -none-            Revertible:            No            LV Name:               Macintosh HD            Volume Name:           Macintosh HD            Content Hint:          Apple_HFSRogers-iMac:~ reberhart$ sudo gpt -vv -r show /dev/disk0WARNING: Improper use of the sudo command could lead to data lossor the deletion of important system files. Please double-check yourtyping when using sudo. Type "man sudo" for more information.To proceed, enter your password, or type Ctrl-C to abort.Password:gpt show: /dev/disk0: mediasize&#x3D;121332826112; sectorsize&#x3D;512; blocks&#x3D;236978176gpt show: /dev/disk0: PMBR at sector 0gpt show: /dev/disk0: Pri GPT at sector 1gpt show: /dev/disk0: Sec GPT at sector 236978175      start       size  index  contents          0          1         PMBR          1          1         Pri GPT header          2         32         Pri GPT table         34          6                 40     409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B     409640  236306352      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC  236715992     262144      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC  236978136          7          236978143         32         Sec GPT table  236978175          1         Sec GPT headerRogers-iMac:~ reberhart$ sudo fdisk /dev/disk0Disk: /dev/disk0 geometry: 14751/255/63 [236978176 sectors]Signature: 0xAA55         Starting       Ending#: id  cyl  hd sec -  cyl  hd sec [     start -       size]------------------------------------------------------------------------1: EE 1023 254  63 - 1023 254  63 [         1 -  236978175] &lt;Unknown ID&gt;2: 00    0   0   0 -    0   0   0 [         0 -          0] unused     3: 00    0   0   0 -    0   0   0 [         0 -          0] unused     4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

Loner T · Answer

Can you post the output of the last two commands for /dev/disk1?

rogerfrommission viejo · Answer

Whoops. Should have caught that myself.Rogers-iMac:~ reberhart$ sudo gpt -vv -r show /dev/disk1Password:gpt show: /dev/disk1: mediasize&#x3D;3000592982016; sectorsize&#x3D;512; blocks&#x3D;5860533168gpt show: /dev/disk1: PMBR at sector 0gpt show: /dev/disk1: Pri GPT at sector 1gpt show: /dev/disk1: Sec GPT at sector 5860533167       start        size  index  contents           0           1         PMBR           1           1         Pri GPT header           2          32         Pri GPT table          34           6                  40      409600      1  GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B      409640  3902082880      2  GPT part - 53746F72-6167-11AA-AA11-00306543ECAC  3902492520     1269536      3  GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC  3903762056         376          3903762432  1956769792      4  GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7  5860532224         911          5860533135          32         Sec GPT table  5860533167           1         Sec GPT headerRogers-iMac:~ reberhart$ sudo fdisk /dev/disk1Disk: /dev/disk1 geometry: 97451/255/63 [1565565872 sectors]Signature: 0xAA55         Starting       Ending#: id  cyl  hd sec -  cyl  hd sec [     start -       size]------------------------------------------------------------------------1: EE 1023 254  63 - 1023 254  63 [         1 - 4294967294] &lt;Unknown ID&gt;2: 00    0   0   0 -    0   0   0 [         0 -          0] unused     3: 00    0   0   0 -    0   0   0 [         0 -          0] unused     4: 00    0   0   0 -    0   0   0 [         0 -          0] unused

Loner T · Answer

BCA has two methods of Windows  installation. 1. Hybrid MBR - This requires Windows to be installed within the first 2TB of the disk. Your partitioning indicates otherwise. 2. EFI - This is supported on Late 2013+ Macs. This requires either BCA to boot the EFI version of Windows installer, or from your Windows Installation media (USB or DVD) selection EFI boot manually. This will also split the designated partition into two parts and FAT MSR (128MB) and the remainder which becomes NTFS. In your specific case, this is also not possible, as you can see the designated Windows partition is beyond the 2TB limit.The BCA seems to have failed leaving you in a bad state. You should use BCA and delete this partition. As a test, if you create a partition of 1.2 TB for Windows, the first 200MB will be within the 2TB limit, which might help and you can try it. Otherwise use EFI installer and leave BCA alone. You will still need to use BC drivers.

rogerfrommission viejo · Answer

I tried previously with the "split drive evenly" option. It failed in similar fashion. Do you think 1.2 TB would be different?Thanks,Roger

Loner T · Answer

If that is the case, the 1.2TB test will also fail. If this is an iMac 5K, you have the ability to install using EFI rather than the legacy method.

rogerfrommission viejo · Answer

Yeah, it&#x27;s 5K iMac. You mentioned above that the EFI method wouldn&#x27;t work because the partition is past the 2 TB limit. Is there a way around that? How do you install using EFI?Thanks.

Loner T · Answer

If you have already built the USB which has BC drivers and the Windows ISO, insert it, and power cycle your Mac and hold the Alt/Option key. You should see four options, OS X, Recovery HD, Windows and EFI boot. Point it to this partition and check if the Installer lets you continue.

rogerfrommission viejo · Answer

Weird. Holding Option is not giving me any options, boots straight to OS X. On a previous attempt it did give me boot options. I&#x27;ll try re-creating the Bootcamp partition and see if it gives me the boot options.

rogerfrommission viejo · Answer

Okay. Re-created the 1tb partition with BCA. Ran into the same problem. Held down Option during the reboot and was able to get into the boot options. Chose the EFI Boot. This took me back to the Windows installer. Failed in exactly the same way, with the exception that it now considered the Bootcamp partition to be Drive 1/Partition 4 instead of Drive 0/Partition 4.

Loner T · Answer

If your BCA partition is from the previous layout that you posted, the issue is that the EFI boot also requires a FAT partition which needs to reside within the first 2TB of the disk. As a test, delete the current partition using BCA, split your disk in half and try the EFI Installer.

rogerfrommission viejo · Answer

Still no go. Created a 1.5tb partition. BCA automatically restarted machine. Selected the bootcamp partition. Windows installer said it had to be formatted as NTFS. Formatted it. Selected the partition again and hit next. Received error. Quit installer. Held down Option. Chose EFI Boot. Went through the same song and dance. Same error.According to the TwoCanoes article, doesn&#x27;t the entire partition have to fall within the first 2.2tb, not just part of it? If that&#x27;s the case, then I&#x27;d have to go to quite a bit of effort to rejigger my drive. Honestly don&#x27;t think it&#x27;s worth it. This computer may be my wife&#x27;s next upgrade while I build a new Windows PC.Here is the error I get every time:

Loner T · Answer

1. Do not use BCA. Remove the current partition using BCA.2. Use Disk Utility and the partition does not need to fit in 2.2 TB if EFI is used. GPT-only disks only need an EFI FAT at the beginning of the disk. The 2.2TB requirement is for Hybrid MBR installations, because MBRs use 32-bit LBAs which cannot handle more than 2.2TB using 512-byte sectors. There are ways around this specific issue as well. The designated Windows partition should be Free Space. 3. Once you create it, use your USB2 disk which has necessary drivers and point to this free space partition for installation.

rogerfrommission viejo · Answer

Can you give more specific steps of what I should be doing in Disk Utility?Thanks.

Loner T · Answer

1. Run DU.2. Click on the current Macintosh HD.3. Click on the &#x27;+&#x27; sign at bottom right and split Macintosh HD into half.4. Select the upper half and create a partition and from the drop down box for  format select Free Space. The DU right pane will have OSX, Grey Blank Space, white OSX Remainder. This can also be down using diskutil cs resizeStack, but it has some quirks.5. Use the USB created by BCA. Power cycle your Mac, and hold the Alt Key. Choose EFI Boot, and select the Free Space chunk created in 4 and Test.6. Please ensure you have your OSX fully backed up, in case it needs to erased/restored.

rogerfrommission viejo · Answer

After splitting the drive into 2 partitions, then selecting the top one, the &#x27;+/-&#x27; buttons are greyed out. If I select the bottom half, the &#x27;-&#x27; button is available, but the plus is greyed out.