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Cannot reinstall Mountain Lion on MacBook in recovery mode: Only Mac OS X Base system available in recovery mode.

I am trying to reinstall Mountain Lion on a 2014 MacBook Air that has crashed. I have booted (successfully) countless times in recovery mode. Have timemachine backups from an external HD, can access the internet etc. The crux is that no disk is available when trying to reinstall. Disk Utility only shows disk0 and the ex dented Mac OS X Base System. Erase is greyed out. Verification is fine. Once a few days ago the HD appeared briefly in Disk Utility (!) and I tried to erase but an error message appeared and I have not seen it since.

I have done all the Google searches for the problem and have not found a solution. The Base System shows 1.19 GB with a little spare space. Because I have a recent back up I just need to erase and reinstall but the erase is the problem. Should I try and create a partition on the Base System? Or a new disk image? I have an even older Mac using 10.6 if that is of help (ie I could create an image on the La Cie HD to boot if that made sense though the La Cie HD has my TimeMachine backups). I am not able to get to an Apple Store for the next few weeks. I think I will need to get a new MacBook but hoping one of the geniuses on this forum might have a solution to saving the old woke! Many thanks in advance.

Posted on Jul 21, 2021 4:31 AM

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Posted on Jul 21, 2021 7:16 AM

Hello, AndrewA1961.


You say the MBA is a 2014 model?

The 2014 can't run Mac OS X 10.8 Mountain Lion. You should be trying to install 10.9 Mavericks or newer.


As for the inability to erase your HD: it sounds as if the startup volume has been corrupted and the OS cannot recognize it.

In Disk Utility, make sure that "Show All Devices" is selected in the View menu.

Then, hopefully, you should be able to select the drive device/media at the top of the list and erase it. If the drive has failed, there is nothing to do but find a way to install the OS on an ext USB drive that you can use to boot the Air. Which then suggests that you'll probably just want to send it in for service or replace it.


If the old laptop is capable of running Mavericks, then you can use it to install the OS onto an ext USB drive.


I would not risk the TM backups by writing any other data or images to the backup drive. Put that aside until you can get the OS installed on the MBA.


EDIT - re: the base system... you can forget that idea if for no other reason than you need at minimum 8GB of storage space to install Mavericks.


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Question marked as Top-ranking reply

Jul 21, 2021 7:16 AM in response to AndrewA1961

Hello, AndrewA1961.


You say the MBA is a 2014 model?

The 2014 can't run Mac OS X 10.8 Mountain Lion. You should be trying to install 10.9 Mavericks or newer.


As for the inability to erase your HD: it sounds as if the startup volume has been corrupted and the OS cannot recognize it.

In Disk Utility, make sure that "Show All Devices" is selected in the View menu.

Then, hopefully, you should be able to select the drive device/media at the top of the list and erase it. If the drive has failed, there is nothing to do but find a way to install the OS on an ext USB drive that you can use to boot the Air. Which then suggests that you'll probably just want to send it in for service or replace it.


If the old laptop is capable of running Mavericks, then you can use it to install the OS onto an ext USB drive.


I would not risk the TM backups by writing any other data or images to the backup drive. Put that aside until you can get the OS installed on the MBA.


EDIT - re: the base system... you can forget that idea if for no other reason than you need at minimum 8GB of storage space to install Mavericks.


Jul 22, 2021 6:08 AM in response to D.I. Johnson

Thank you so much. Very helpful. I think it is a 2014 MBA but cannot check right now for obvious reasons. But in recovery mode the 10.8 Mountain Lion option is the one that pops up. The problem is no disk gets presented in the box on which it can be installed. Same problem with the backups. For Disk Utility the only disk showing is the disk0 then Mac OS X Base System. If I plug in the external HD, the La Cie shows up, so I know it is working.

The old MB is so old it is pre-Mavericks. I will heed your advice and preserve the backups on the La Cie external disk and take the machine into Apple London when I return next week and see what they can do. Will just have to function on the iPhone until then. Thanks again for your help.

Cannot reinstall Mountain Lion on MacBook in recovery mode: Only Mac OS X Base system available in recovery mode.

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