GPT partition of type "unknown" found, will not touch this disk

[carson.sears29]

Hello I am hoping to get some help with a problem I have been having installing ubuntu on my Macbook Pro I am pretty new to all this and I am getting pretty frustrated trying to figure this out. I was able to make the CD boot it with the help of rEFit install ubuntu 13.10 and then restart my computer after installation. I then went into the rEFit partition inspector tool to verify my partitions and I came up with the error message "GPT partition of type "unknown" found, will not touch this disk." I have tried various things like gdisk and gptsync and had a hard time figuring out both and still no solution.

this is what i am looking at and not sure how to proceed.


*** Report for internal hard disk ***


Current GPT partition table:
# Start LBA End LBA Type
1 40 409639 EFI System (FAT)
2 409640 887782839 Mac OS X HFS+
3 968568832 976771071 Linux Swap
4 887783424 887785471 GRUB2 BIOS Boot
5 887785472 968568831 Unknown


Current MBR partition table:
# A Start LBA End LBA Type
1 1 409639 ee EFI Protective
2 409640 887782839 af Mac OS X HFS+
3 968568832 976771071 82 Linux swap / Solaris
4 * 887783424 887785471 83 Linux


MBR contents:
Boot Code: GRUB


Partition at LBA 40:
Boot Code: None (Non-system disk message)
File System: FAT32
Listed in GPT as partition 1, type EFI System (FAT)


Partition at LBA 409640:
Boot Code: None
File System: HFS Extended (HFS+)
Listed in GPT as partition 2, type Mac OS X HFS+
Listed in MBR as partition 2, type af Mac OS X HFS+


Partition at LBA 968568832:
Boot Code: None
File System: Unknown
Listed in GPT as partition 3, type Linux Swap
Listed in MBR as partition 3, type 82 Linux swap / Solaris


Partition at LBA 887783424:
Boot Code: None
File System: Unknown
Listed in GPT as partition 4, type GRUB2 BIOS Boot
Listed in MBR as partition 4, type 83 Linux, active


Partition at LBA 887785472:
Boot Code: None
File System: ext4
Listed in GPT as partition 5, type Unknown



Thank you in advance for any help you can offer.

[oldfred]

Not sure how it works with a Mac.

About 2/3 way down is list of actual GUIDs:
http://en.wikipedia.org/wiki/GUID_Partition_Table

Perhaps using gdisk you created a 8300 as the new data type and your MAC does not recognize it. The 4 digit codes seem to be a short version of the very long UUIDs.
Change type code to 8300 with dual booting with Windows on gpt
http://www.rodsbooks.com/linux-fs-code/index.html

What does gdisk show?

[hawkmage]

It looks like it could be the OS X Recovery partition. With the introduction of OS X Lion Apple implemented a recovery partition with a minimal install of OS X so you can recover your system volume.