How to turn a physical OS X (El Capitan) (with data) into a Virtual Machine

[PeaceFreak]

I have a bootable backup of El Capitan on an external hard disk (about 430Gb with applications that will not function on Catalina) that I would like to turn into a virtual machine.

Can anyone walk me through the steps needed to achieve this?

Thanks in advance!

[asajm]

Hi PeaceFreak​

Check maybe help

convert an os x running os mac to a virtual machine in order to run in Fusion

[ColoradoMarmot]

So a 430 GB virtual machine is going to have challenges.  My suggestion would be to first move any data files off that system to a regular external hard drive - shrink the used space on the machine image.

The good news is that it's on a separate external drive, that makes the process pretty easy.  Just create a new El Cap virtual machine in fusion.  When it gets to the migration wizard (*before* you create a user), plug in the external USB drive and migrate from it to the new virtual machine.

I've tried a bunch of methods, and that's the one that works the best by far.

One note - there isn't any 3d acceleration for OSX guests, so if you have graphics programs that expect it (or messages for example), you may get either strange behavior or outright failure to work.

[PeaceFreak]

Thanks for your responses.

Dlhotka are you saying that VM Fusion is slow with large virtual machines? I was not aware of that, if it's true...

I've been struggling with the link that ASAJM suggested as the procedure was not so clear, so I'm glad for this alternative...

Will give it a try sometime in the next 24 hours...

[ColoradoMarmot]

I generally try to keep my VM's under 100 GB on Fusion, but they can definitely go larger.   Bigger VM's can be, well, unwieldy.  That's a lot of virtual disk to manage and backup (you have to do a full copy - not time machine, not incremental to have a reliable one).  I'm probably overly limiting from long-past glitches 🙂

[PeaceFreak]

Thanks, understand about backing up and will do a full copy.

Having trouble creating a 500GB virtual machine to transfer my data into (The total size of the disk is actually 430GB).

When creating a VM, the default size if 40GB, and I can't find a way to change it... I have tried changing the size to 500GB through the VM control panel, after installing OSX but before migrating the date. (If I "get info" on the VM it says the size is around 550GB, but once I start the data transfer is says there is not enough space)

I've tried quitting Fusion but that does not help...

Any thoughts on how I might resolve this?

Thanks!

[ColoradoMarmot]

You have to change the disk size after setting the OS, but before you actually start the VM - just go into settings and change the disk size there.

[PeaceFreak · Accepted solution]

Thanks for everyone's help. I was finally able to copy my bootable backup of El Capitan to a virtual machine, and it's now working fine!

It seems that when a virtual machine is made, the OS is kept in its own separate 40GB partition/container. If you make the virtual machine disk size larger, that extra space is set into a separate partition/container.

For me, this meant that even after shutting down the virtual machine and increasing the disk size to 512 GB, I was still not able to migrate my backup to the virtual machine. I would get an error message saying there was not enough space. The reason this was happening was because VM Fusion was trying to copy the backup data to the 40GB partition/container, not the empty portion with the free space.

What was needed was to find a way to combine the 40GB section with the additional free space into one continuous disk.

How I resolved this turned out to be reasonably easy...

1/ Go through the process of creating a new virtual disk using an installer for the operating system you want to use. In my case I used my Install OS X El Capitan.app that I had saved on an external hard disk.

2/ When the language selection window appears, shut down the virtual machine.

3/ Go to Virtual Machine in the menubar and choose "Settings". Click on "Hard Disk" in the "Removable Devices" section (there may be two hard disks listed, choose the ~40GB).

4/ Change the disk size to a size that matches (or is larger than) the size of the backup you want to install. Click Apply.

5/ Click on "Advanced options" and choose "Pre-allocate disk space". Click Apply. Be patient, it will take time to create to create the new partition/container, especially if it is hundreds of GBs.

6/ Close the "Settings" window.

7/ Quit VM Fusion (This step may not be necessary, but I did it to make sure everything was reset.)

8/ Restart VM Fusion, then start the virtual machine you are making.

9/ You will probably see the language selection window again. Choose the language you want to use, then click the arrow which will take you to the "MacOS Utilities" window.

10/ Choose "Disk Utility" rather than "Install MacOS" and click "Continue".

11/ Click on "Partition", you'll see the the 42GB section (which you cannot adjust) and the extra space labeled "Free space" that you added in step 4 above.

12/ Click on the "Free space" section, then click on the minus button below it. All the space will be allocated to the main disk and it will have become a single partition.

13/ Click on "Apply" in the bottom right corner of the window. In the warning sheet that appears click on "Partition".

14/ Next you want to erase that partition so that all the free space is available. Click on the disk in the left column, if it is not already selected, then click on "Erase" in the middle top of the right section of the window. In the warning sheet that comes up, click on "Erase". You now have all the space available for migrating your backup!!

15/ Quit Disk Utility.

16/ In the "MacOS Utilities" window click on "Install MacOS", then click on "Continue".

17/ The installation window will appear for the version of the OS you are installing. Click on "Continue", and agree to the usual licensing agreements.

18/ In the next window you will be able to see the hard disk you created with the size listed below it. Click on it the click on "Install" and the installation will begin.

19/ Once the installation is complete, you will see the "Welcome" window. Choose the country, click "Continue", choose the keyboard, click "Continue", which will bring you to the migration window (Transfer Information to This Mac).

20/ Connect the external hard disk with your bootable backup to the computer. (Depending on your VM Fusion settings a window may come up asking you to choose which computer to connect it to.) Choose the virtual machine. Though you may not see it, your disk should now be accessible by the virtual machine.

21/ In the migration window, select "From a Mac, Time Machine backup, or startup disk" and click "Continue".

22/ In the next window, select your external disk, and click "Continue".

From that point on, the rest of the steps should be straightforward...

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