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reubs

macrumors 68000
Original poster
Jun 22, 2006
1,884
213
Last week I tried to install Yosemite onto an external drive that I had in order to take a look at it and try it out. The installation went great, my MBP rebooted, and I was looking at a new OS on an external disk. I played with it for a few minutes, decided it was time to do real work, and shut down my system.

I unplugged the external drive, and when I rebooted my MBP, Yosemite began to install on my MBP as my main OS. I thought, "Surely this can't be happening," but after a few minutes I was staring at Yosemite on my main computer with no recourse because I had, I though, taken all of the proper precautions.

It's not a huge deal, but I wonder how many other folks this might have happened to, or if there was some major step that I missed completely that I need to know about for next time.
 

S.B.G

Moderator
Staff member
Sep 8, 2010
26,635
10,397
Detroit
Did you plug the external drive back in and see if Yosemite is actually on it?
 

chabig

macrumors G4
Sep 6, 2002
11,434
9,299
SandboxGeneral brings up a good question. I suspect you directed the install onto the main drive, thinking you were directing it to the external drive. When you unplugged the external, the only way Yosemite would complete its installation is if that were the case. If you plug the external back in I bet there is no Yosemite installation on it.
 

reubs

macrumors 68000
Original poster
Jun 22, 2006
1,884
213
Nope; 10.10 is on both of them. I was VERY careful to make sure I pointed the install to the "Clone Trooper" drive instead of Macintosh SSD. I don't know how it happened or why, but it did.
 

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kolax

macrumors G3
Mar 20, 2007
9,181
115
When it reboots, it would've booted into your Macintosh HD unless you held 'option' at boot and told it to boot off the USB drive.

I think you may have installed it to both drives without realising?
 

reubs

macrumors 68000
Original poster
Jun 22, 2006
1,884
213
When it reboots, it would've booted into your Macintosh HD unless you held 'option' at boot and told it to boot off the USB drive.

I think you may have installed it to both drives without realising?

Yeah, that's what happened, but I can't understand why the installer was still running, does that make sense? I guess I just thought that after it installed on the Clone Trooper drive then it would quit and I wouldn't have to worry about it running on the Macintosh SSD.
 

kolax

macrumors G3
Mar 20, 2007
9,181
115
Yeah, that's what happened, but I can't understand why the installer was still running, does that make sense? I guess I just thought that after it installed on the Clone Trooper drive then it would quit and I wouldn't have to worry about it running on the Macintosh SSD.

How did you do the Yosemite upgrade? From a USB stick or did you run it via the Mac App Store?
 

reubs

macrumors 68000
Original poster
Jun 22, 2006
1,884
213
How did you do the Yosemite upgrade? From a USB stick or did you run it via the Mac App Store?

The beta from the App Store; I guess that's what happened. Should've put it on the USB stick and then taken it out. Didn't think about that.
 
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