User profile for user: NemesysSoftware
NemesysSoftware Author
User level: Level 1
18 points

The startup disk cannot be partitioned or restored to a single partition

I've read multiple posts about this happening when your startup disk is already partitioned.


My problem is that the startup disk IS NOT partitioned. I specifically installed a clean version of El Capitan on an external FW disk and it is not partitioned. So, why am I getting this message? I don't want to install on my internal disk, I have a Thunderbolt drive that I would like to use for that. I thought that this was possible?

MacBook Pro, OS X El Capitan (10.11)

Posted on Nov 21, 2015 11:48 AM

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22 replies
User profile for user: Loner T
Loner T
User level: Level 9
59,536 points

Nov 21, 2015 11:51 AM in response to NemesysSoftware

NemesysSoftware wrote:


I've read multiple posts about this happening when your startup disk is already partitioned.


My problem is that the startup disk IS NOT partitioned. I specifically installed a clean version of El Capitan on an external FW disk and it is not partitioned. So, why am I getting this message? I don't want to install on my internal disk, I have a Thunderbolt drive that I would like to use for that. I thought that this was possible?

Are the FW and TB disks the same or different disks? Are you using a TB-to-FW adapter? What year/model is your Mac?

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User profile for user: Loner T
Loner T
User level: Level 9
59,536 points

Nov 21, 2015 12:52 PM in response to NemesysSoftware

1. It would be better to boot OSX from the internal disk, rather than the external FW disk. The FW disk should be disconnected.

2. The TB drive should not be connected via any other TB devices (like TB hubs). Directly connect it to the MBP.

3. You do not need BCA, if you do not want to use it. A FAT partition on the TB disk, with an appropriate MBR will let you install W7 from by booting from the DVD and pointing to the TB partition for Windows.

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User profile for user: Loner T
Loner T
User level: Level 9
59,536 points

Nov 25, 2015 7:06 AM in response to NemesysSoftware

MBR = Master Boot Record. On Macs, to support Windows and legacy BIOS, the partition table is mapped to a MBR in a 1:1 mapping, called a Hybrid MBR. This needs to be also created after the partition is created. Newer versions of Disk Utility will also create a MBR when a FAT32 partition is created.


Try via DU first, and from OSX Terminal check the output of sudo fdisk /dev/disk0 . Enter your password when prompted, and it will not be echoed back to you.

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User profile for user: NemesysSoftware
NemesysSoftware Author
User level: Level 1
18 points

Nov 25, 2015 7:09 AM in response to Loner T

Havent' had the time to spend on this. But my goal is to have a 100GB FAT32 partition on the Thunderbolt disk and the rest of the 6TB will be a journaled HFS+. From what you're saying, it seems that if I create a FAT32 partition on the TB disk, this MBR will be automatically created by DU? Maybe that's why I'm getting this error message in Boot Camp when I try to do the work from BC. My internal disk is partitioned in 2 and both partitions are HFS+. So, based on your explanation, I guess there is no MBR and maybe that's why Boot Camp doesn't want to proceed?


Frankly, for an app that is supposed to help you and has the ability to resize and create partitions, you would think BC would be able to do whatever it needs...

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User profile for user: Loner T
Loner T
User level: Level 9
59,536 points

Nov 25, 2015 7:26 AM in response to NemesysSoftware

NemesysSoftware wrote:


From what you're saying, it seems that if I create a FAT32 partition on the TB disk, this MBR will be automatically created by DU? Maybe that's why I'm getting this error message in Boot Camp when I try to do the work from BC.

This is dependent on DU versions. The Fdisk command can be used to verify the suitability of the disk structure created/modified.

My internal disk is partitioned in 2 and both partitions are HFS+. So, based on your explanation, I guess there is no MBR and maybe that's why Boot Camp doesn't want to proceed?

This will cause two issues. On a Mac, BIOS-based Windows versions (W7, W8+) cannot be installed on a disk which already has two user-visible partitions. W8 supports EFI installations, so it can installed on a GPT-only disk. W10 also supports EFI.

Frankly, for an app that is supposed to help you and has the ability to resize and create partitions, you would think BC would be able to do whatever it needs...

There are only so many variants BCA understands. Any variant outside such a list is new and is not handled well. External disks cause the most issues with BCA. BCA works well on a standard Mac. The more user-modifications, the less likely it is to work.


Please post the output of the following commands with all the storage that you have currently connected.


diskutil list

diskutil cs list

sudo gpt -vv -r show /dev/disk0

sudo fdisk /dev/disk0


The "sudo" commands will prompt for your password, and it will not be echoed back. You may also see a warning about improper use of "sudo" and potential data loss due to "abuse" of the command.

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User profile for user: NemesysSoftware
NemesysSoftware Author
User level: Level 1
18 points

Nov 25, 2015 7:39 AM in response to Loner T

Sorry for the green on black!


laurent@Laurents-MacBook-Pro-3:~> diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_CoreStorage Mac OS X 599.5 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

4: Apple_HFS MyData 399.7 GB disk0s4

/dev/disk1 (internal, virtual):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS Mac OS X +599.1 GB disk1

Logical Volume on disk0s2

0FC9A146-CFF7-44BB-ACD1-516EDDC70577

Unencrypted

/dev/disk2 (disk image):

#: TYPE NAME SIZE IDENTIFIER

0: ESD-ISO +3.3 GB disk2

/dev/disk4 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *3.0 TB disk4

1: EFI EFI 209.7 MB disk4s1

2: Apple_RAID 3.0 TB disk4s2

3: Apple_Boot Boot OS X 134.2 MB disk4s3

/dev/disk5 (disk image):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme +157.3 MB disk5

1: Apple_HFS DivX for Mac 157.2 MB disk5s1

/dev/disk6 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *3.0 TB disk6

1: EFI EFI 209.7 MB disk6s1

2: Apple_RAID 3.0 TB disk6s2

3: Apple_Boot Boot OS X 134.2 MB disk6s3

/dev/disk7 (external, virtual):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS My Book Thunderbolt... +6.0 TB disk7

/dev/disk8 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: *1.0 TB disk8

/dev/disk9 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_partition_scheme *250.1 GB disk9

1: Apple_partition_map 32.3 KB disk9s1

2: Apple_HFS Extra 250GB 249.9 GB disk9s3

/dev/disk10 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk10

1: EFI EFI 209.7 MB disk10s1

2: Apple_HFS MyBook 1TB 999.9 GB disk10s2

/dev/disk11 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *6.0 TB disk11

1: EFI EFI 209.7 MB disk11s1

2: Apple_HFS MyBook 6TB 6.0 TB disk11s2


laurent@Laurents-MacBook-Pro-3:~> diskutil cs list

CoreStorage logical volume groups (1 found)

|

+-- Logical Volume Group 4CB364CB-190A-4558-AE9B-94D1A89FA55B

=========================================================

Name: Mac OS X

Status: Online

Size: 599484215296 B (599.5 GB)

Free Space: 729088 B (729.1 KB)

|

+-< Physical Volume 7209C3E6-D604-45CD-AD10-9D9D8EDC23F1

| ----------------------------------------------------

| Index: 0

| Disk: disk0s2

| Status: Online

| Size: 599484215296 B (599.5 GB)

|

+-> Logical Volume Family E7DF5F4D-D8F1-4A4A-B18C-73D8E1E3CF95

----------------------------------------------------------

Encryption Type: None

|

+-> Logical Volume 0FC9A146-CFF7-44BB-ACD1-516EDDC70577

---------------------------------------------------

Disk: disk1

Status: Online

Size (Total): 599131160576 B (599.1 GB)

Revertible: No

LV Name: Mac OS X

Volume Name: Mac OS X

Content Hint: Apple_HFS


laurent@Laurents-MacBook-Pro-3:~> sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=1000204886016; sectorsize=512; blocks=1953525168

gpt show: /dev/disk0: PMBR at sector 0

gpt show: /dev/disk0: Pri GPT at sector 1

gpt show: /dev/disk0: Sec GPT at sector 1953525167

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 1170867608 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

1171277248 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

1172546784 780716200 4 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

1953262984 262151

1953525135 32 Sec GPT table

1953525167 1 Sec GPT header


laurent@Laurents-MacBook-Pro-3:~> sudo fdisk /dev/disk0

Disk: /dev/disk0 geometry: 121601/255/63 [1953525168 sectors]

Signature: 0xAA55

Starting Ending

#: id cyl hd sec - cyl hd sec [ start - size]

------------------------------------------------------------------------

1: EE 1023 254 63 - 1023 254 63 [ 1 - 1953525167] <Unknown ID>

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

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User profile for user: Loner T
Loner T
User level: Level 9
59,536 points

Nov 25, 2015 10:11 AM in response to NemesysSoftware

1. You have MyData on disk0. This precludes Windows installation of this disk.

2. You have RAID set(s), which should not be connected when installing Windows.

3. You may be able to install Windows on external TB disks.

4. Your 2011 Mac will only support BIOS/MBR Windows. EFI Windows is not supported. Partial EFI installations will lead to unknown devices and driver issues on your specific 2011 Mac.

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User profile for user: NemesysSoftware
NemesysSoftware Author
User level: Level 1
18 points

Nov 25, 2015 10:25 AM in response to Loner T

Loner,


Many thanks. You seem to know what you're talking about!


A few remaining questions:


1. So, if I was to reformat my internal drive as one partition, then I would be able to install a Windows partition that could be managed by Boot Camp?

2. Not a problem. Would I have to disconnect it only for the installation or each time I would like to boot in Windows?

3. I may be able to install Windows on the external TB. Why just "may be"? Is it possible that it could fail?

4. Not too sure I understand the differences between BIOS/MBR and EFI. What I'd like to know is once the Windows partition is installed, suppose on the TB drive, would I be able to hold Option when booting and have the choice to boot from Windows?

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User profile for user: Loner T
Loner T
User level: Level 9
59,536 points

Nov 25, 2015 11:00 AM in response to NemesysSoftware

1. If you move MyData to a different disk, you can install Windows on the internal disk. Please ensure you have a good backup of disk0.

2. Just for the installation. The RAID set will be inaccessible from Windows, since Apple RAID drivers do not exist for Windows.

3. Yes, it can fail. It entirely depends on the TB chain. A direct link is the most viable option. TB makes the external disk look like a PCI disk, which is supported. Windows requires a reboot to see TB hardware on older Macs. Since you will boot from it, there is no hot-plugging issue in your specific case. Please also see Thunderbolt ports and displays: Frequently asked questions (FAQ) - Apple Support and check the Bootcamp Q&A.

4. W8 and W10 support EFI boot using the UEFI standard. 2011 Macs do not fully support UEFI. Late 2013 and later models are UEFI compliant. Please see http://www.intel.com/content/www/us/en/architecture-and-technology/unified-exten sible-firmware-interface/efi-specificati… .Yes Option/Alt will work, as long as the TB is connected when the Mac is powered up. I would recommend hot-plugging of TB disk in your case.

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The startup disk cannot be partitioned or restored to a single partition

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