Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Hi guys,

I'd like to install Yosemite on my 2011 air, but I'm not quite brave enough to go all out and install over my current internal mavericks OS.

I have a usb3 external SSD that I was wondering if I can clean install Yosemite onto it and then boot from that for the time being to see if I like it?

I realise my Air only has usb2, but its more to have a go at using the OS for a few days before doing the update properly.

How is best to go about it?

Thanks very much!
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,477
16,186
California
Hi guys,

I'd like to install Yosemite on my 2011 air, but I'm not quite brave enough to go all out and install over my current internal mavericks OS.

I have a usb3 external SSD that I was wondering if I can clean install Yosemite onto it and then boot from that for the time being to see if I like it?

I realise my Air only has usb2, but its more to have a go at using the OS for a few days before doing the update properly.

How is best to go about it?

Thanks very much!

Yes that will work, but like you mentioned, it will be very slow. During the install there is a step where it asks where you want to install and you just point that to the external drive.
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Thanks for your help. I now have Yosemite on a portable drive which seems to be working really well.

Going back to the mac which I installed it from, now the Yosemite drive has been taken out, it doesn't see the correct drive any more.

I can see my TM drive plugged in, system recovery 10.9.1 and OSX installer. Where's my current OS!?

Thanks!
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,477
16,186
California
Thanks for your help. I now have Yosemite on a portable drive which seems to be working really well.

Going back to the mac which I installed it from, now the Yosemite drive has been taken out, it doesn't see the correct drive any more.

I can see my TM drive plugged in, system recovery 10.9.1 and OSX installer. Where's my current OS!?

Thanks!

Do a command-r boot to recovery and from there set the startup disk to the Mavericks volume. Look in the menus, I think it is in the Utilities menu?
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Do a command-r boot to recovery and from there set the startup disk to the Mavericks volume. Look in the menus, I think it is in the Utilities menu?

Brilliant, thanks. That saved me an afternoon restoring from TM. I never knew there was that option under the apple logo!
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Thanks for the help with that. I'm happy enough to move the external Yosemite drive onto the internal Macbook Air drive now.

What's the best way of doing that?

I'm thinking a Time Machine restore might be best?

Thanks!
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,477
16,186
California
Thanks for the help with that. I'm happy enough to move the external Yosemite drive onto the internal Macbook Air drive now.

What's the best way of doing that?

I'm thinking a Time Machine restore might be best?

Thanks!

Yep... that would do the trick (assuming yu are using the TM backup made with Yosemite). Just option key boot to the TM disk then use Disk Util to erase the drive and click restore.
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Yep... that would do the trick (assuming yu are using the TM backup made with Yosemite). Just option key boot to the TM disk then use Disk Util to erase the drive and click restore.

Brilliant. I'm doing a TM backup of the Mavericks install atm just in case!

My Yosemite TM drive was backing up both the Yosemite SSD and the old Macintosh HD internal so it looks like this inside the TM drive:

Backups.backups
>...
>...
>Latest
>>Macintosh SSD (Yosemite external)
>>Macintosh HD (Mavericks internal)

When I follow your instructions above, will it know to only restore the Yosemite drive?

Thanks again!
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
You know... Im not sure what it would do in that case. I would make a new backup of only Yosemite to restore from if it was me.

So I have a TM backup of both OSs. I've gone through the instructions above and am in the process of restoring from Time Machine.

I'm on a grey screen with the Apple Logo and a bar, which has been at 50% for several hours. Googling the issue implied that it was frozen and to force power off and on, but when turning on again it is back to that screen at 50%.

Can I assume it is working properly and just copying everything back onto the mac?

Thanks!
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,477
16,186
California
So I have a TM backup of both OSs. I've gone through the instructions above and am in the process of restoring from Time Machine.

I'm on a grey screen with the Apple Logo and a bar, which has been at 50% for several hours. Googling the issue implied that it was frozen and to force power off and on, but when turning on again it is back to that screen at 50%.

Can I assume it is working properly and just copying everything back onto the mac?

Thanks!

Hmmm... not good. No movement at all for hours on end. I would start over and erase the drive again.
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Hmmm... not good. No movement at all for hours on end. I would start over and erase the drive again.

It will be restoring 400gb over USB2 - still not good?

I wondered whether it was one of those bars which works left to right as it does tasks, so roughly 50% through is the 'transfer data' task.
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
I did the reboot option key to see the list of available drives.

It sees the restored drive, recovery drive and time machine. For kicks I clicked on the restored drive and it takes you to the grey Apple screen and bar. It goes reasonably quickly the first third, then rather slow to the middle and then seems to stop.

Start again?

Edit. Started again. Hopefully it's there ready and working in the morning..!
 
Last edited:

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,477
16,186
California
I did the reboot option key to see the list of available drives.

It sees the restored drive, recovery drive and time machine. For kicks I clicked on the restored drive and it takes you to the grey Apple screen and bar. It goes reasonably quickly the first third, then rather slow to the middle and then seems to stop.

Start again?

Edit. Started again. Hopefully it's there ready and working in the morning..!

Hope so. Even with USB speeds, that should not take more than 5-6 hours tops.
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
Hope so. Even with USB speeds, that should not take more than 5-6 hours tops.

Nope. Stuck on the boot up screen at 50%...

Could it be something to do with the OS being on an external drive, and I'm trying to TM restore it to the internal drive?

Is there anything else I can try?
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
I found this thread:

https://discussions.apple.com/thread/6606897?start=0&tstart=0

and tried resetting the PRAM etc, but that doesn't change anything.

On closer inspection, the log for repairing permissions on the restored drive comes up with:

"unable to set owner and group on "Library......alf.plist";error 1: Operation not permitted"

and

"unable to set permissions on "Library/pref......alf.plist";error 1: Operation not permitted"


Going to the apple logo and choosing the start up disk comes up with a window with no choice of start up disk too.

The disk utility window says that the internal drive is 175gb full, where as the TM estimate for how big the external yosemite drive is 230gb....

So I've wiped the Yosemite Time machine, and am starting again!

Hopefully it was just something that didn't transfer over to time machine. Instead of starting a fresh TM backup rather than having both drives on the TM as you suggested above, I deleted the backups of the internal drive. Perhaps more went than should have...

My only other thought is that I installed Yosemite onto this external drive from a different computer, then plugged the external Yosemite drive into the Air and started using it, but its been working fine on this current computer for well over a week now.

If this fails, what other options do I have to get this external drive onto my internal drive? Migration assistant? Cloning?

Thanks once again!
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
34,477
16,186
California
My only other thought is that I installed Yosemite onto this external drive from a different computer, then plugged the external Yosemite drive into the Air and started using it, but its been working fine on this current computer for well over a week now.

That should not matter.

If this fails, what other options do I have to get this external drive onto my internal drive? Migration assistant? Cloning?

Try this. On the Air hold command-option-r when booting. It will ask for your wifi info then you will see spinning globe while the Internet recovery utility downloads. Then the recovery screen will come up.

Now start Disk Util and format/erase the internal disk to Mac OS Extended (Journaled). Now go to the restore tab and with the Yosemite installed disk attached, drag that disk to the source and the internal to destination and click restore. That will clone the Yosemite disk to the internal.

The only catch there is the external Yosemite volume must be slightly smaller than the internal disk size since DU does a block by block clone and not a file clone. So if you need to, just use DU to resize the Yosemite volume down to just under the size of the internal Air disk.
 

thecounthahaha

macrumors regular
Original poster
Jul 17, 2010
156
8
That should not matter.



Try this. On the Air hold command-option-r when booting. It will ask for your wifi info then you will see spinning globe while the Internet recovery utility downloads. Then the recovery screen will come up.

Now start Disk Util and format/erase the internal disk to Mac OS Extended (Journaled). Now go to the restore tab and with the Yosemite installed disk attached, drag that disk to the source and the internal to destination and click restore. That will clone the Yosemite disk to the internal.

The only catch there is the external Yosemite volume must be slightly smaller than the internal disk size since DU does a block by block clone and not a file clone. So if you need to, just use DU to resize the Yosemite volume down to just under the size of the internal Air disk.

So I did a full fresh TM backup and it worked this time. Not sure what happened before, but it was only transferring 175/240gb across to the internal according to the recovery disk utility. Weird.

Thanks very very very much for the help, its all working well now!
 

billboquet

macrumors newbie
Dec 27, 2006
8
1
Installed on usb2 external drive with migration assistant using a Mavericks Time machine backup, took something like 3 hours but everything went fine, Nothing is missing, and surprisingly very fast on external drive.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.