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I’m upgrading my OS X 10.11 (El Capitan) beta to the GM candidate on my MacBook Pro (last year's model, all original hardware) which has a dual-boot setup with Ubuntu. After the installer reboots my computer, I get:
OS X could not be installed on your computer
A boot helper partition is required when working with Core Storage.
Quit the installer to restart your computer and try again.
I have tried restarting my computer but the same error message appears each time. My guess is that the Ubuntu partition is causing this. I’m using rEFInd to boot into it.
Where has my boot helper partition disappeared (whatever that is), and how can I reinstall OS X on the partition it was previously installed on without touching the Ubuntu setup?
Output of diskutil list
:
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *251.0 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_CoreStorage Macintosh HD 232.8 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Linux Filesystem 17.2 GB disk0s4
/dev/disk1 (internal, virtual):
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS Macintosh HD +232.5 GB disk1
Logical Volume on disk0s2
464DCBB2-E35B-48E3-A123-B6B8C755E0F2
Unencrypted
Output of sudo gpt show -l /dev/disk0
:
gpt show: /dev/disk0: Suspicious MBR at sector 0
start size index contents
0 1 MBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - "EFI System Partition"
409640 454699328 2 GPT part - "Macintosh HD"
455108968 1269536 3 GPT part - "Recovery HD"
456378504 33594064 4 GPT part - "Linux"
489972568 262151
490234719 32 Sec GPT table
490234751 1 Sec GPT header
Output of sudo fdisk /dev/disk0
:
Disk: /dev/disk0 geometry: 30515/255/63 [490234752 sectors]
Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: EE 0 0 1 - 1023 254 63 [ 1 - 409639] <Unknown ID>
*2: AF 1023 254 63 - 1023 254 63 [ 409640 - 454699328] HFS+
3: AF 1023 254 63 - 1023 254 63 [ 455108968 - 1269536] HFS+
4: 83 1023 254 63 - 1023 254 63 [ 456378504 - 33594064] Linux files*
Please use
gpt
andfdisk
to show us your partition tables. – Spiff – 2015-09-14T03:36:22.837diskutil
is not equivalent tofdisk
.fdisk
specifically interprets the MBR as an MBR with no knowledge of GPT, which is helpful for debugging multi OS boot setups. Especially whengpt
flags the MBR as suspicious. – Spiff – 2015-09-14T11:19:19.1471I had the same issue. Ended up having to reinstall OS X (as GM). The catch is that I refind doesn't seem to be working for El Capitan GM (errors when blessing the boot parition/file) so if you're like me and use EFI STUBS and the refind_linux.conf to boot (grubless) it might not be possible any more. – amanthethy – 2015-09-14T13:38:10.080