"Missing Operating system_ " After installing Yosemite

Can you post the output of sudo gpt -vv -r show /dev/disk0?

gpt show: /dev/disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: /dev/disk0: Suspicious MBR at sector 0

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

gpt show: /dev/disk0: Sec GPT at sector 976773167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 857910152 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

858319792 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

859589328 1328

859590656 117182457 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

976773113 22

976773135 32 Sec GPT table

976773167 1 Sec GPT header

abughareeb wrote:

gpt show: /dev/disk0: mediasize=500107862016; sectorsize=512; blocks=976773168

gpt show: /dev/disk0: Suspicious MBR at sector 0

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

gpt show: /dev/disk0: Sec GPT at sector 976773167

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 857910152 2 GPT part - 48465300-0000-11AA-AA11-00306543ECAC

858319792 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

859589328 1328

859590656 117182457 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

976773113 22

976773135 32 Sec GPT table

976773167 1 Sec GPT header

The highlighted entry does not look correct. Did you do a 'w' (to write) and 'y' (to confirm) the Gdisk update? It should look like the following.

sudo gpt -vv -r show /dev/disk0

Password:

gpt show: /dev/disk0: mediasize=256060514304; sectorsize=512; blocks=500118192

gpt show: /dev/disk0: Suspicious MBR at sector 0

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

gpt show: /dev/disk0: Sec GPT at sector 500118191

start size index contents

0 1 MBR

1 1 Pri GPT header

2 32 Pri GPT table

34 6

40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B

409640 250392096 2 GPT part - 53746F72-6167-11AA-AA11-00306543ECAC

250801736 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC

252071272 664

252071936 248045568 4 GPT part - EBD0A0A2-B9E5-4433-87C0-68B6B72699C7

500117504 655

500118159 32 Sec GPT table

500118191 1 Sec GPT header

Notice the long string after "2 GPT Part".

After I did the adjustment I tried:

- (Recovery mood) MacOS x partition is missing in disk utility and I can only see boot camp. In fact, the entire partition looks as if it is free space.

- Now I can see the OSX folder in boot camp tool.

- I can see the OSX partition if I press alt during boot.

But I would still get the same gray no entry result. Please I don't want to lose my files. I haven't made backups. Do you have an idea why it's not letting me in.

In Recovery console, can you Verify and Repair the disk?

No, unfortunately not.

You can re-install OSX on the current OSX partition which will not modify any of you existing files or Windows. You should try this carefully, since you do not have backups.

Will do, but just do it as careful as I can could you please provide me with the steps. Thanks Loner for helping me solve my problem.

Boot into Internet Recovery (Command+Opt+R). Choose Re-install OSX. Make sure it gives the same OSX version as what you currently have on the internal disk. Select the internal partition which currently has OSX and re-install. If the installer wants to erase the disk (not the partition) stop and post back.

I dont understand why Apple hasn't sent any update to squish this bug!

I can't see the partition drive I can only see boot camp. The reinstall utility doesn't allow me to select Mac OS X's partition . 😕 what should i do ?

This is helping me as well waiting anxiously for the next steps... 🙂

jrnavid wrote:

I dont understand why Apple hasn't sent any update to squish this bug!

Environmental issues contribute as well. There is not a single fix. CS volumes and Disk Utility do not play nicely together. Yosemite should have stayed in incubation for another year. 😉

abughareeb wrote:

I can't see the partition drive I can only see boot camp. The reinstall utility doesn't allow me to select Mac OS X's partition . 😕 what should i do ?

Is it possible to post a screen shot? If your GPT has GPT 2 as CS, the Recovery Console should let you choose it.

Can you also post a screen shot of diskutil cs list?

jaggboy wrote:

This is helping me as well waiting anxiously for the next steps... 🙂

If you are able to follow this, that is excellent, but if you need to start a new discussion, feel free to do so.