Dtyjlui

I'm completely new to Ubuntu, but after owning an iMac for the best part of 7 years and having it slow down on me I thought I'd give Linux a go.

I downloaded Ubuntu 18.04 and burned a DVD. In macOS disk utilities I partitioned my hard drive and called the new partition Ubuntu. I then installed reFind. This works I tried rebooting and my macOS operating system comes up.

I then rebooted the iMac with the Ubuntu installation DVD in, but I didn't get the nice modern installation screen that Ubuntu says I should get, instead I get a very similar one to what the Ubuntu installation guide says I might get instead. I selected install Ubuntu, and again didn't get the nice installation options, Ubuntu just started installation. I didn't get any options of installing it on my new partition.

I got through eventually to the desktop, and thought everything had worked, but the next time I switched on my computer reFind just showed macOS as the only operating system. It's almost like I didn't install Ubuntu at all I just tried it from the disk.

Below is the output from the command diskutil list.

/dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *500.1 GB   disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:                  Apple_HFS Macintosh HD            200.0 GB   disk0s2

   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

   4:       Microsoft Basic Data UBUNTU                  299.1 GB   disk0s4

What should I do? Thanks!!!

Pete

Below is an example of how to install Ubuntu on a 2011 iMac. Here, I assume you only have macOS installed. You may notice that the images were created using VirtualBox. However, you will be installing directly to the internal drive. I did actually install Ubuntu to my 2011 iMac's internal drive. The VirtualBox images are as close as I could come to reproducing what I saw.

Note: To be a better view of an image, either click on the image or open the image in a new window.

For this example, the output from diskutil list disk0 is shown below.

 /dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *536.9 GB   disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:                  Apple_HFS Macintosh HD            235.9 GB   disk0s2

   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

   4:       Microsoft Basic Data UBUNTU                  299.9 GB   disk0s4

1. 
   

   Use the Disk Utility application to erase the UBUNTU volume. Choose a format of Mac OS Extended (Journaled), as shown below.

   
   
   

   

   
   

Afterwards, diskutil list disk0 produced the result shown below. This will insure disk0 is not hybrid partitioned.

    /dev/disk0 (internal, physical):

       #:                       TYPE NAME                    SIZE       IDENTIFIER

       0:      GUID_partition_scheme                        *536.9 GB   disk0

       1:                        EFI EFI                     209.7 MB   disk0s1

       2:                  Apple_HFS Macintosh HD            235.9 GB   disk0s2

       3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

       4:                  Apple_HFS UBUNTU                  299.9 GB   disk0s4

2. 
   

   Insert the Ubuntu 18.10 DVD. The macOS operating system will not be able to read the DVD. This is normal. When the popup shown below appears, click on the Ignore button.

   
   
   

   

   
   



3. Restart the Mac. Immediately hold down the option key until the Startup Manager icons appear. Select the DVD icon labeled EFI boot. If there are two DVD icons labeled EFI boot, then choose either one.



4. 
   

   When image shown below appears, select Try Ubuntu without installing. If you wait long enough, this choice will be made for you.

   
   
   

   

   
   


5. 
   

   When the image shown below appears. Open the icon labeled Install Ubuntu 18.10.

   
   
   

   
   

   Note: My iMac was hardwired to the internet though the Ethernet jack. If you rely on Wi-Fi, then make the appropriate changes to these instructions.

   
   

   
   
   

   

   
   


6. 
   

   Answer the questions until you reach the image shown below. Select Install third-party software for graphics and Wi-Fi hardware and additional media formats. When you have made the same selections as shown below, click on Continue.

   
   
   

   

   
   


7. 
   

   Select Something else. When you have made the same selections as shown below, click on Continue.

   
   
   

   

   
   


8. 
   

   Highlight the Device /dev/sda4, shown below. Next, click on the Change... button.

   
   
   

   

   
   


9. 
   

   In the popup window, do not change the Size:. You should change Use as: to Ext4 journaling file system and Mount point: to /. Also, check off Format the partition:, as shown below. When finished, click on the OK button.

   
   
   

   

   
   


10. 
    

    The result is shown below. Next, click on the Install Now button.

    
    
    

    

    
    


11. 
    

    Select the Continue button shown in the image below.

    
    
    

    

    
    


12. 
    

    In the image shown below, select your time zone, then click on the Continue button.

    
    
    

    

    
    



13. Answer any additional questions and allow Ubuntu to finish installing.

Comment on Changing the Default Operating System

You invoke the Startup Manager by holding down the option key at startup. To make an operating system the default, hold down the control key before making your selection.

Ubuntu will appear in the Startup Manager as an internal drive icon with the label EFI boot.