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djqbert53

macrumors newbie
Original poster
Oct 20, 2014
23
0
Hey guys,

I just wanted to reinstall Yosemite but after a while had the error "This core storage operation is not allowed" . Thanks in advance everyone.
 
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Unfortunately I cant even open OS X its the only way I can access to terminal.

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As much as I understood won't show anything about HD itself. Recovery HD symbol is locked.
 
First thing in the morning did internet recovery but on last 18 minutes i had the error with core storage operation afterwards erased ssd. I do have an ext hdd seagate can i install it from there? Btw there is no backup.
 
First thing in the morning did internet recovery but on last 18 minutes i had the error with core storage operation afterwards erased ssd. I do have an ext hdd seagate can i install it from there? Btw there is no backup.

You can install OS X to the external drive and boot from it to access the internal drive's contents and back it up to the Seagate.
 
Can you please give more details about the process? Which type of file extension should it have and how can I change the boot order? I've tried it in the morning but the only thing appears is recovery mode. Doesnt have much more than that. Not even safe mode gets open.
 
Sorry friend i dont have it

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My drive is unaccesable right now and all my data is backed up already so all i want to do to partition my drive to reinstall yosemite.
 
Sorry friend i dont have it

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My drive is unaccesable right now and all my data is backed up already so all i want to do to partition my drive to reinstall yosemite.

Well you're not going to get anywhere without:

1. A second working Mac.
2. A bootable OS X environment (requires a second Mac to make this)
3. A bootable USB OS X installer (also requires a second Mac to make it).
 
I ll try on friends Mac but my disk is unreadable and recovery hd is locked. How that will be help me?
 
I ll try on friends Mac but my disk is unreadable and recovery hd is locked. How that will be help me?

What you need to do with a second Mac is to actually install OS X on an external USB drive, so that you can start up from the USB drive to access the internal drive's contents.

Download the Yosemite installer from the App Store, run it and when prompted, install it in the external drive (format it as Mac OS Extended - Journaled).
 
Allright if i plug in my thumb drive and install yosemite from recovery it works. Pressed to alt key and chosed start from usb but the problem is i cant select Hard disk because there is no one to choose.
 
Allright if i plug in my thumb drive and install yosemite from recovery it works. Pressed to alt key and chosed start from usb but the problem is i cant select Hard disk because there is no one to choose.

Let's back up a bit. Do a command-option-r to get to Internet recovery. Now in the Utilities menu select Terminal. Now type the below text exactly like I have it in Terminal then enter. That will kill off the logical volume you have locked up on there.

Code:
diskutil cs delete "drive name"

Now quit Terminal and launch Disk Util and go to the erase tab and select the disk in the left column and Mac OS Extended (Journaled) in the dropdown then apply that format.

Now quit Disk Utility and select reinstall OS X. This will get you back to the OS that came from the factory and you can upgrade from there.
 
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Everything worked perfectly Weaselboy but now its installing Yosemite after all. Is it ok? Its mbp early 2013

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Because in the morning i had core storage operation is not allowed error
 
Everything worked perfectly Weaselboy but now its installing Yosemite after all. Is it ok? Its mbp early 2013

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Because in the morning i had core storage operation is not allowed error

If it is installing okay now, let's know rock the boat. :) I would let it finish and see if it works out.
 
Weaselboy your solution helped me out. Got my Yosemite back thank you very much.
 
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