Way to switch Mac OS boot partitions without going through System Preferences

1) Resize your OSX Partition, leave the space created as freespace (i.e don't create any partition)

2) Write the iso to USB and boot it (take the most recent image from http://cdimage.ubuntu.com)

3) Create ext4 for / where the freespace was created, use sda1 (osx: disk1s1) or use another EFI if you have more then 1 drive and you want to use the second for linux only - in short: use the EFI partition as the "bootloader" partition

4) Install Ubuntu (or any other distro) - but watch for the bootloader, if you don't want to use grub (care to elaborate, why?) you need to rebless the volume in os'x to boot through the normal bootscreen where you can hold ALT to fire linux.

I don't know what you want to achieve with that, since having grub is basically the same, and you will be loading grub from that screen anyways since you need to load the kernel somehow - guess there are other options but I never used them, just went with grub.

What I mean is that after you select the other partition with the normal bootscreen by holding ALT, you will load grub - since you must load the kernel, and there is now way to load it directly from that screen other then using MBR which even makes less sense since it's a UEFI system ;-)

note: I strongly advise you to use refit - it's a very good solution and has some extra functionality that will make multi-os setup's boot better.

If you don't like it, just rebless the volume in os x and you get rid of it. bless is a system command- however in the new os x there is:

sudo systemsetup -liststartupdisks

and to setup back any Volume as the sys volume use:

sudo systemsetup -setstartupdisk /Volumes/YOUR_SYS_VOLUME_NAME

to check if it worked:

sudo systemsetup -getstartupdisk

So even if something goes FUBAR with the bootloader, it won't be any problem.

Why would you reinstall os x or anything else to boot linux on a Mac?!? Anyone doing reinstallations to boot linux is just a windows impared user who does not know how unix works, what gpt is and thinks of EFI as fancy bios.

Update 9

Good news, your "Recovery HD" volume has the correct identifier of disk0s3. So there is nothing to fix.

I would not assume the "Boot Camp Support Software", you can download using the Boot Camp Assistant application, is the same as the Boot Camp Support Software 5.1.5621" required for Windows 7. Although, for my (21.5-inch, Mid 2011) iMac, I happen to know they are the same.

If you properly constructed your USB installer, you should be able to use the Boot Camp Assistant to install Windows 7. Both my iMacs require installing using a DVD, so you are on you own here.

If you choose not to use the Boot Camp Assistant, the insert the USB installer and restart the computer. Hold down the alt/option key and select the icon labeled Windows. From the installer, you can reformat the BOOTCAMP partition NTFS. If the computer boots back to OS X, select the Windows partition from the Startup Disk panel in System Preferences. Click on "Restart..." to continue the installation of Windows. Once you have completed the Windows installation, but sure to install the "Boot Camp Support Software" stored the the USB drive. I believe the setup.exe application can be found in the BootCamp folder on the USB drive.

Update 8

You repaired the file system on your "Macintosh HD" volume. This repair does not fix any files that may have been damaged while the HFS file system was corrupted. In cases like this, it may become necessary to backup your personal files (which may also be damaged), erase the entire disk and reload OS X.

For future reference, it is generally not a good idea to try to verify or repair a file system on the same volume that you have booted from. The computer basically is trying to verify or repair a file system that who knows how many programs are also read from and write to. The preferred method to verify or repair is to boot from a different volume. From your post, I see your probably already learned this.

The Apple site regarding firmware is About EFI and SMC firmware updates for Intel-based Mac computers.

Do do not think you explained how you created the USB Windows installer. You were able to boot from a USB port so you must have done something right. I was questioning if you also included the Boot Camp Support Software on the same USB drive. This software for Windows 7 can be found at Install Windows 7 and earlier on your Mac using Boot Camp. These files need to placed on the drive per step 11 in the section titled "Perform a new install of Windows 7".

I do not know why you should not try using the Boot Camp Assistant to install Windows 7. The application does preform many of the a tedious steps involved in installing for you.

If you choose not to use the Boot Camp Assistant, then the next step would be to create a FAT formatted partition to hold Windows 7. This can be done using the Disk Assistant application as already explained in Update 7.

Unfortunately, it would appear the command I wanted you to enter did not complete. The last image you posted shows the "Recovery HD" volume has the identifier of disk0s4. The correct value should have been disk0s3. Could you post the output from the command below, so I can verify this is not just false output from the command you entered.

sudo  gpt  -r  show  /dev/disk0

Update 6 and 7

From the result of your Update 5, I can see you have successfully removed Windows from your Mac. The output you posted from the gpt command shows there is about 100 GB of free space on your internal drive. I can not find a way to make the El Capitan (OS X 10.11) Disk Utility application recover this space. This was not a problem with the previous versions of OS X. Fortunately, the command line version still seems to work. Enter the following command in a Terminal application window. Before entering the command, I would make sure the Disk Utility application is not currently running.

sudo  diskutil  resizevolume  /dev/disk0s2  R

If successful, the missing 100 GB should be added back to your "Macintosh HD" volume. If not, let me know and I will post an alternative solution.

I assume you now what to do a BIOS/MBR install of Windows 7 without the aid of the Boot Camp Assistant. I assume you made sure your firmware is up to date and that the USB Windows installer contains the correct files.

The reason you received an error message, during your latest attempt to install Windows, is because your MBR table is configured as a Protective Master Boot Record (PMBR) table. A PMBR table is defined as having a single partition of type EE that spans the entire disk except for the MBR itself. The command fdisk shows your disk contains 1465149168 sectors (blocks). The MBR resides in first sector starting at index 0. The EE partition resides in the remaining 1465149167 sectors. The purpose of a PMBR table is to prevent legacy software from accidentally modifying your MBR partition table. The occurrence of a PMBR also indicates to modern software that you have a GPT.

The cylinder (cyl), head (hd) and sector (sec) columns in the MBR table are no longer used to represent the geometry of the disk (drive). Most of the time, the values stored are just made up and therefore ignored. The EFI specification does give default values for the type EE partition, but I believe Apple and Microsoft ignore these values.

To install Windows in BIOS/MBR mode, you need a FAT or NTFS formatted partition stored in the fourth partition in the MBR table. Since OS X can not format a partition as NTFS, you will have to settle for a FAT format. The easiest way to create such a partition is with the Disk Utility. Below is an example using a 100 GB disk image. You will need to apply the same steps using your internal drive.

1. Highlight the drive.

2. Click on the button labeled Partition. A window similar to what is shown below should appear.

   

3. Make the appropriate adjustments to create a "MS-DOS (FAT)" partition. This is where you are going to install Windows. Below is a proposed new 20 GB partition.

   

   Make sure you still have your original "Macintosh HD" partition, as shown below, then click the "Apply" button.

   

4. Your results should be similar to the image shown below.

   

The creation of this new partition should populate your MBR table. When installing Windows, you will be able to reformat this "BOOTCAMP" partition as NTFS.

Note: To add partitions to the MBR requires reducing the size of the protective type EE partition to end at the same sector (block) as the EFI partition in the GPT. Any additional MBR partitions will also be mirrored in the GPT. One consequence, of reducing the size of the EE partition, is some lost of a PMBR. Legacy software now has the opportunity to incorrectly partition your drive. The Windows operating system falls into the category of this legacy software. Therefore, it is important you do not change the drive partitioning using any software provided by Microsoft. However, it is OK to format partitions.

One final note. Resizing a volume that is currently set as the computer's startup disk may invalidate that setting. Since this is your startup volume, you can eliminate this possibility by following the steps below.

1. Open System Preferences.
2. Open the Startup Disk panel.
3. If necessary, click on the lock to make changes.
4. Click on the icon labeled "Macintosh HD" to highlight it.
5. Quit System Preferences.

Below is an image of my highlight El Capitan startup disk highlighted.

By the way, as some point during a Windows installation, your computer may boot back to OS X. If if does, return to this Startup Disk panel and highlight the Windows disk, then select "Restart...". Your Windows installation will continue.

Update 5:

Here is the link to "Create a bootable installer for OS X".

To Download the OS X installer from the Mac App Store, do the following. Open the "App Store" application and enter "el capitan" in the search box. The resulting window should appear similar to the image shown below.

Click on the "DOWNLOAD" button below the title "OS X El Capitan". Follow the instructions to start the download.

Note: You can enlarge an image by clicking on it. Or, you can open the image in a new window.

You will need a 8 GB or larger USB flash drive. Before entering the command

sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app

you should initialize your flash drive. The steps are given below.

1. Insert the flash drive into a USB port.
2. Open the "Disk Utility" application.
3. Highlight the icon representing the flash drive media.
4. Select the icon labeled "Erase".

5. Configure for a single visible partition be setting "Name:", "Format:" and "Scheme:" as shown below.

   

6. Click on the "Erase" button.
7. When finished, quit the "Disk Utility" application.

Update 4:

You probably can eliminate the icon labeled "EFI Boot", shown in your Update 2, by following the instructions, in the section titled "Chasing Ghosts", given at this link.

Update 3:

According to Apple web site Computers that can be upgraded to use OS X Internet Recovery, MacBook Pros have be able to use OS X Internet Recovery since 2010. Granted, a firmware upgrade may be needed, but I do not think this applies to your MacBook Pro (13-inch, Mid 2012) model.

Update 2:

On my Mac, I can not use the gpt command to edit the GPT on a disk, while booted from a partition on the same disk. I assume you will have the same problem, if you boot to a recovery partition on your Macs internal disk. One solution would be to boot from a USB flash drive and then enter the diskutil and gpt commands.

One way to create this USB flash drive would be to download and execute the OS X Recovery Disk Assistant v1.0. Unfortunately, this software only works with Lion through Yosemite. El Capitan can still boot to Recovery Mode from a USB flash drive, but the software download, needed to create this flash drive, exceeds 6 GB. Basically, you download and transfer to a USB flash drive all the software needed to boot to Recovery Mode and install the current version of El Capitan. Of course, all you need is to boot to Recovery Mode. You do not need to reinstall El Capitan.

Also, from System Preferences, select Start Up Disk. Highlight your OS X boot partition (Macintosh HD) and restart the computer. This should fix your boot problem.

Before executing the steps in Update 1, do the following. Boot to your internal recovery partition. From the menu bar, select "OS X Utilities" and then "About OS X Utilities". Copy down the version number and post it for me to read.

Next, open a Terminal application window. Enter the following command and post the results.

mount  |  grep  disk0

This will tell me which recovery partition you are booting from. Would not want you to delete the wrong one.

Update 1:

I assume the second recovery partition is not needed. If you want to check, you can try booting from both first. If successful, then it is probably safe to remove the second one. To boot from a recovery partition, restart the computer and hold down the alt/option key. Select an icon to choose the partition to boot from.

To remove the unneeded partitions, you need to boot from internet recovery. The instructions are given at the site OS X: About OS X Recovery. Once you are in internet recovery, open a Terminal application window and enter the following commands.

diskutil  unmountDisk  /dev/disk0
gpt  remove  -i  4  /dev/disk0
diskutil  unmountDisk  /dev/disk0
gpt remove  -i  5  /dev/disk0

This should return the computer to a state where the Boot Camp Assistant can be used to install Windows. If you fail, we can discuss other means to install Windows.

Answers to Questions

Answer to question 1:

The hidden EFI partition was created when OS X was installed. The Mac does not use this partition to boot OS X. It is used by OS X when you upgrade the firmware or format a different partition. Do not remove this partition. The partition is used if you install Linux or install Windows using the EFI/GPT boot method. This method is suppose to work if installing Windows 10. It is not suppose to work if installing Windows 7. Windows 7 is suppose to be installed using the legacy BIOS/MBR method.

Answer to question 2:

The Apple_Boot partitions are hidden recovery partitions. There should only be one on your computer per OS X installation. The recovery partition should always be next partition after the OS X partition. Neither belong to Boot Camp. My guess would be you removed an older OS X partition and did not remove the hidden recovery partition. You boot to a recovery partition by holding down the alt/option key at startup. Icons will appear allowing you to select a recovery partition to boot to. Recovery partitions have may uses such as reinstalling or repairing your current OS X installation. Since you have a newer Mac, you can also boot to recovery mode directly over the internet.

Answer to question 3.

When installing Windows 7, you have to choose either partition 2, 3, or 4. If you have a recovery partition and are using the Boot Camp Assistant, you are limited to only the 4th partition. While it is possible to manually install to a partition greater than 4, the amount of grief involved makes it not worth bothering to try.

There are two partition tables stored on the drive. One is the legacy Master Boot Record (MBR) partition table and the second is the GUID Partition Table (GPT) where GUID stands for Globally Unique Identifier. OS X uses the GPT and Windows 7 uses the MBR partition table. You have posted the partitions on your drive as seen by only looking at the GPT.

If you have a FAT or NTFS formatted partition, then the legacy MBR partition table needs to be updated to reflect this. I suspect this did not happen or the values are wrong. The message "it's a GPT partition style" was generated because the Windows 7 installer sees your drive as having a GPT format.

Usually, the Disk Utility and/or the Boot Camp Assistance will make the proper changes to the MBR partition table when a FAT formatted partition is created. Note, the GPT can hold 120 entries while the MBR partition table can only hold 4 entries. Once the proper entries are made to the MBR partition table, Windows and its installer will see the drive as only having a MBR partition scheme.

From my experience, the Boot Camp Assistant will not work properly while the 5th partition exists on your drive.

Beyond answering your questions, you need to enter the following commands at a Terminal application window. Edit your question to post the results. If prompted, enter your login password. None of these commands will change your computer. The commands will print out most of the contents of the both partition tables.

sudo  gpt  -r  show  /dev/disk0
sudo  fdisk  /dev/disk0