Help, restored Macintosh HD to OS X Base System

Help! I accidentally restored Macintosh HD to OS X Base System. Didn't know that would cause issues... I can only open my laptop through the Command+R thing with macOS Installer.


I was just trying to delete everything and start my Macbook fresh. I tried to re-install OS X Sierra, and it keeps failing. When I go to disk utility under internal, there's no Macintosh HD there's only OS X Base System.


Tried to ask Apple Support for help and they first told me to try first aid and that failed.

They told me to go to a service center, but I wanted to see if there are any solutions I could try.

Thanks!


It's a 2015 Macbook Pro.

Posted on Feb 11, 2017 4:55 PM

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Posted on Feb 11, 2017 7:53 PM

The OS X Base system should be a disk image a little over 2 GB in size. Is that all you see? Maybe indented under something called "Apple disk image Media".


So do you also see a hard disk icon identified by a brand name, such as "Apple SSD"? If so, when you highlight it, what does it say in the white box underneath in terms of partition map and capacity? Is it called "disk0" at the bottom right? Does it look like it might be your real hard drive?


If so, what happens if you try to erase it? You should get a drop down that gives you a place to enter a name (Macintosh HD), a format that says "Mac OS Extended (Journaled), and a scheme called "GUID Partition Map". If this is really your hard drive, then this step should recreate your Macintosh HD volume.


If that works, you should be able to continue with the installation of macOS.


Good luck!

42 replies
Question marked as Top-ranking reply

Feb 11, 2017 7:53 PM in response to minjun1014

The OS X Base system should be a disk image a little over 2 GB in size. Is that all you see? Maybe indented under something called "Apple disk image Media".


So do you also see a hard disk icon identified by a brand name, such as "Apple SSD"? If so, when you highlight it, what does it say in the white box underneath in terms of partition map and capacity? Is it called "disk0" at the bottom right? Does it look like it might be your real hard drive?


If so, what happens if you try to erase it? You should get a drop down that gives you a place to enter a name (Macintosh HD), a format that says "Mac OS Extended (Journaled), and a scheme called "GUID Partition Map". If this is really your hard drive, then this step should recreate your Macintosh HD volume.


If that works, you should be able to continue with the installation of macOS.


Good luck!

Apr 13, 2017 7:15 PM in response to minjun1014

Hi to anyone else who accidentally restored the macintosh he with the OS X base System here are a few steps to follow to hopefully resolve your issues:


• enter internet System recovery be restarting your MacBook and immediately pressing control+option+R.

• wait for it to load and the macOS utilities or OX S utilities should pop up.

• then enter the driver utilies

• under internal where it says OS X base System, click erase

• rename the drive Macintosh HD

• make sure the format is Max OS Extended (Journaled)

• hit erase one more time

• Then exit driver utilities

• Enter Reinstall MacOS Sierra or Reinstall OS X

• Then Select the Macintosh HD drive

• Reinstall MacOS Sierra or Reinstall OS X

• finally your MacBook should be back to normal and good as new.

Jan 12, 2018 4:53 AM in response to minjun1014

Just had exactly the same problem... Turn on the computer and hold down “Cmd + Alt + R” to enter internet recovery mode. Select reinstall operating system, reinstall it to the OS X Base System and it should run.


I followed Wafflefallafle’s instructions but they wouldn’t work on my Mid 2011 iMac as it wasn’t the internet recovery mode just the Cmd + R recovery which isn’t the same thing. Mine is now restoring :-)

Jul 31, 2017 1:22 AM in response to WaffleFallafle

Hi there, does anyone know of a way to do this without Internet System Recovery? I have had the exact same problem but on an old 2009 iMac so it only has the standard recovery process (CMD + R). I need to restore my old "Macintosh HD" to /dev/disk0 instead of only seeing the OS X Base System. Trawling through online forums, people have had this sort of problem when there's a HDD failure or a cable problem, but mine is a direct result of restoring the OS X Base System over the primary internal drive.

Aug 21, 2017 2:28 AM in response to WaffleFallafle

I'm trying to follow these steps but when I try to the "OSX BaseSystem" drive I can't. The fields for entering the name and format type are greyed out and the erase button is greyed out too. Any idea why this may be?

I'm wondering whether the "restore" function would allow me to put the OSX Base System back (where it belongs?) in the folder directly beneath my "Apple HDD ST....." drive?

Would that be a wise move?

Sep 13, 2017 2:14 PM in response to WaffleFallafle

I didn't restore my mac with the OS X base, I just turned it on and it would not start. I have been trying everything and can't get it to do anything except with command R, it goes to the disk utility, but it gives me no options. It only shoes the OS X as a hard drive and does not let me erase it, or change its name, when I do a repair it does it very quickly and nothing happens. I can't use my time machine back up, it says it can't find it.

What else can I do? any tips?

Nov 9, 2017 10:31 AM in response to WaffleFallafle

Hi WaffleFallafle


I have a MacBook Pro 15’ 2017 and I have the same problem posted in this foro


I got stuck on the step

• under internal where it says OS X base System, click erase


When I try to Erase the volume it says "This operation can not be performed because you can not unmount the volume you are booted from”. I can’t unmount as well.


I was traying to erase by terminal with the command:


diskutil eraseVolume JHFS+ Macintosh HD /dev/disk0s2


But I got the answer it can’t be unmount.


When I type the commond diskutil list this is what I get:

-bash3.2# Diskutil list

/dev/disk0 (internal):

#: TYPE NAME SIZE IDENTIFIER

0: GUI_partition_scheme 500.6 GB disk0

1: EFI EFI 314.6 MB disk0s1

2: Apple_HFS X Base System 499.3 GB dsik0s2


How I can do to reformat the disk to JHFS+, name as Macintosh HD and then install Mac OS on my notebook.


Thanks for your answer.

Feb 6, 2018 6:20 AM in response to minjun1014

I tried Date changing and other solutions but nothing works. Do not try anything else but first give it a go. I’m sure this will work for pretty much everyone.

Solution is easy,

Erase the drive with using name (Macintosh HD),

Format the Drive and it should be Max OS Extended (Journaled),

Repair Os Base System image file before installing the OS on Macintosh HD.

(Do not change anything else or to anything else)

This will take around 15 minuets and later 10 more to setting up the OS.

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Help, restored Macintosh HD to OS X Base System

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