So I installed a second HDD that I plan on eventually using as my main system disk and did a fresh install of Yosemite on it. The thing, is that I'd like to boot back into the original Macintosh HD so I can start going through what needs to be migrated. I can browse the disk through finder (at least the folders I have permission for), but I can't boot off of it anymore. When I go to Systems---> Settings--> Startup disk. Only the new drive is listed. Even if I reboot and hold down option, it's the same thing.

Did something happen to to the original Macintosh HD disk after installing Yosemite on a separate drive?

I'm just worried that even if I can't boot into it anymore, I'd still like to be able to pull stuff from my old home folder, but it's saying I don't have permission. What's the workaround for that? I'm using the same login credentials on the new installation that I was on the old one.

  • did you try to bless the system on the internal disk?
    – klanomath
    Nov 1 '14 at 2:23
  • Nope. I'll look into it though. Nov 1 '14 at 3:18

Open up Terminal.app, in /Applications/Utilities, and enter the following:

diskutil list

It should show both of your drives and give you information about partitions. You may also want to try:

diskutil cs list

On Yosemite, some of the volumes are defaulting to Core Storage, which can span multiple drives. I'm not saying you did this, in fact I rather doubt, or at least hope you didn't, was inadvertently convert both drives to a single, huge volume that's really two drives.

I use Scannerz and it comes with another drive management tool called Phoenix. In their release notes for the Yosemite version they said that some systems earlier than Mavericks may not fully be able to see or manipulate files on a Yosemite volume, but a Yosemite volume is supposed to see and be able to manipulate. In other words, if you boot from, say Mountain Lion, you may not be able to do what you want to on a Yosemite volume. I know this is true for stuff in the low level system directories, but I'm not sure it effects user volumes. Maybe they'll put something about this on their web site, but then again, maybe not. I'm not convinced this isn't a Yosemite bug of some sort.

If it looks like your volume is intact using diskutil, you might want to restart the system, and immediately hold down the alt key and keep holding it down. A list of bootable volumes should show up and with luck you should then be able to select it and boot from it. Be careful though trying to copy some stuff to the Yosemite volume because like I said the preceding paragraph, it may not work.

  • Thanks for the reply. I checked. Both drives and all their partitions show up in diskutil list. The second command gives back No CoreStorage logical volume groups found. Holding alt/option down shows both drive's "recovery" partitions, but not the boot partition. The old drive was running Yosemite as well. I just wanted to do a clean install on an new SSD which is how I ended up where I am. Nov 1 '14 at 12:28
  • Well, at least we know the drive wasn't converted to Core Storage. For the drive that had the earlier OS on it, did diskutil show the actual volume that existed as still being present and did it look the right size in gigabytes?
    – ElTorosDog
    Nov 1 '14 at 21:32
  • Yeah it looked fine. I'm seeing now that my user's folder is actually in a "recovered items" folder. I must have done something wrong when installing the OS on the new drive. If I could just get into my Library folder I should be ok and can get what I need off of it. I also have a time machine backup of the drive but Time Machine isn't letting me browse it, it only asks if I want to use it as a backup volume for the new installation. I'm not quite ready to do that yet until I know I've gotten everything that I need from the old drive. Nov 2 '14 at 2:47
  • See my comments in the new post below. They were apparently too long to put in the comments section.
    – ElTorosDog
    Nov 3 '14 at 0:08

In an attempt to resolve the issue I would try installing rEFIt which is helpful for inspecting and modifying the regular boot setup.

I've used it for doing dual installs of OSX/Linux in the past.


You can access the backups folders from a working system (at least on Mavericks) as follows. For this example I'm going to use the name "Backups" to represent your Time Machine volume. Here are the steps:

  1. From Finder, click on the "Go" menu item.
  2. From the drop down list, select the "Go to Folder..." option.
  3. Enter the name of the Backup, so for this examples it's:


  1. A Finder window should open with the name "Backups.backupdb". Double click on it.
  2. You should see a folder with the name of your system on it, double click on it.
  3. A list of all your backups should show up. I would think you would want the one named "Latest" but whichever one you want, double click on it.
  4. You should see a folder with the name of the drive on your old system. Double click on that.
  5. At this point you navigate it just like you would navigate a regular drive.

When you find what you want, you can drag it over to anyplace you want to, but you'll have to enter an admin ID and password.

One caveat: Apple started hiding the "Library" directory from people in their home folders. You may actually have to enter that entire path name in from the base of the Backup. On the other hand you may be able to yank all that stuff out by copying over your entire users folder.

Hope this helps.

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