How do I clean install Yosemite?


michelg1970

macrumors regular
Jul 26, 2011
192
42
Gouda - The Netherlands
I wanted to do the same thing and ended up googling (make usb installation yosemite -or something like it) on the subject.

I made external USB drive (i used a hard disk but you can also use USB thumb or even SD card)

There are 3 methods:

the lion disk maker tool (didn't work for me)
the terminal command way (didn't work for me)
the disk utility way (worked for me)

I ended up with an external hard drive that was able to boot an external Yosemite installation and from there i was able to clear all my hard drives and do the full clean install.

Now my rMBP is running very niceeeeeeeeee. Wanted to do clean install coz I installed all the betas over and over again and wanted to start from scratch.

Good luck!

PS you can only do internet recovery if you had already installed yosemite (final version) other wise it will revert to your previous eligible installation (mavericks)
 

TigerMSTR

macrumors regular
Sep 30, 2014
223
58
Couldn't you create a second partition to install Yosemite on, and once the installation is complete delete the Mavericks partition.
 

Swagged

macrumors regular
Original poster
Nov 14, 2011
145
0
Gotham City, New York
I wanted to do the same thing and ended up googling (make usb installation yosemite -or something like it) on the subject.

I made external USB drive (i used a hard disk but you can also use USB thumb or even SD card)

There are 3 methods:

the lion disk maker tool (didn't work for me)
the terminal command way (didn't work for me)
the disk utility way (worked for me)

I ended up with an external hard drive that was able to boot an external Yosemite installation and from there i was able to clear all my hard drives and do the full clean install.

Now my rMBP is running very niceeeeeeeeee. Wanted to do clean install coz I installed all the betas over and over again and wanted to start from scratch.

Good luck!

PS you can only do internet recovery if you had already installed yosemite (final version) other wise it will revert to your previous eligible installation (mavericks)
Ok I installed Yosemite (final version) over my Mavericks so I can simply just do an internet recovery instead of having to create an external usb or use external drive?
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,147
8,813
California
Ok I installed Yosemite (final version) over my Mavericks so I can simply just do an internet recovery instead of having to create an external usb or use external drive?
You should now be able to command-r boot to recovery then erase Macintosh HD in Disk Util then reinstall. Since you are booted from the Yosemite recovery partition, that would get you a clean install of Yosemite.
 
Last edited:

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,147
8,813
California
I had a typo in there (not/now)... since you already installed Yosemite it should have created a Yosemite recovery partition. If you command-r boot to that you can erase the Yosemite partition and reinstall. That will get you a clean install.

Sorry about the confusing typo. :eek: