13 Replies Latest reply: Jun 1, 2012 12:25 PM by Linc Davis
Mr_Pie_Guy1234 Level 1 (5 points)

Okay, story time.


On my mid-2009 macbook pro, I decided to replace my Windows bootcamp with Ubuntu. Removing bootcamp went okay. After that, I installed a program called rEFIt, which lets you choose what you want to boot to every time you boot up, and manage your partitions too. I installed linux, but after running into some driver problems, I decided to uninstall. I uninstalled it, removed the partition, and removed rEFIt, too. Everything appeared to be normal. I noticed that when I pressed Get Info on my Macintosh HD, it said the total size was 90 GB, when the real size of the partition is 120 GB. I thought that was a little odd, but didn't think much of it at the time. A few weeks later, I was trying to create a new partition with Disk Utility, and it said I had to repair the disk. So I booted into the recovery partition and clicked repair disk. It then immediatly said "Alert: This disk does not contain a efi system partition. If you want to start up your computer with this disk, back up your data and repartition this disk.". The funny thing is, I could still start up normally. I then decided to look at diskutil and see if anything in there helped. Here's what I got:


   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *160.0 GB   disk0

   1:                  Apple_HFS Macintosh HD            129.2 GB   disk0s1

   2:                  Apple_HFS Recovery HD             650.0 MB   disk0s2

   3:                        EFI                         209.7 MB   disk0s3


Okay, everything looks normal here. I am totally stumped on what to do, since the EFI appears to be there and there aren't any other partitions. Any advice?

MacBook Pro, Mac OS X (10.7.4)
  • Linc Davis Level 10 (192,206 points)

    No, that isn't normal. Normal would be this:


    #:                       TYPE NAME                       SIZE       IDENTIFIER
       0:      GUID_partition_scheme                        *500.1 GB   disk0
       1:                        EFI                         209.7 MB   disk0s1
       2:                  Apple_HFS Macintosh HD            499.2 GB   disk0s2
       3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3


    The Linux installer wrecked your partition table, as usual. You have to repartition the drive and restore from backups.

  • Mr_Pie_Guy1234 Level 1 (5 points)

    Isn't there a way to move the efi partition up the list or something without reinstalling everything? Sorry, I'm sort of new at this.

  • Linc Davis Level 10 (192,206 points)


  • ds store Level 7 (30,325 points)

    rEFIt hasn't been updated in like forever and it worked for 10.6, but not updated for 10.7, not sure if it even works anymore.


    You can't use a Linux installer for Windows or generic PC's on a Mac, it confuses the MBR portion of your GUID as a real MBR and then goes about installing stuff into EFI thinking it's a Linux swap partition.


    rEFIt has to be installed first, reboot twice, then partitions created on the drive from a external boot source, two for Linux (one swap), one for OS X 10.6 which later gets updated to 10.7




    Your going to have to get all data off the machine, and erase the entire drive and install 10.6, then upgrade to 10.7 again to rebuild your partition maps and that will place EFI in the proper location.


    Good thing, you can Carbon Copy Cloner your


    Apple_HFS Macintosh HD        129.2 GB   disk0s1


    to a blank external drive first and later option key boot off it to reverse clone onto the internal Macintosh HD  when Lion get reinstalled anew from AppStore, so that saves your rebuilding Lion partition again with all your programs, files, tweaks etc.


    How to revert your Mac to Snow Leopard


    How to erase and install Snow Leopard 10.6



    Also you perhaps should use a virtual machine for Linux if your not seasoned enough with it yet.


    Installing Linux on a Lion Mac is a pain, much harder than a 10.6 box. Quite a challenge, use on a spare machine until you get the hang of it.


    Want to try Linux?, read this



    I had 10.7, 10.6, Linux and Windows Vista all running on the same Mac once, and hopefully will once again once I fix the hardware issues on my spare box.

  • Linc Davis Level 10 (192,206 points)

    I guess I should add that you don't necessarily need to reinstall 10.6 in order to reinstall 10.7. If you have a Time Machine backup on a local drive that was started before you destroyed the partition table, you can boot from it into Recovery by holding down the option key at the startup chime.


    If you don't have such a backup, your best option is to get a friend with a Mac running Lion to run Recovery Disk Assistant and make a bootable USB device. Boot from that and do the repartioning/reinstallation/restoration.


    Caution: All data on the USB device will be erased.


    OS X Lion: About Lion Recovery Disk Assistant

  • ds store Level 7 (30,325 points)

    Wonder how CCC would clone the EFI, Recovery HD and Macintosh HD partitions when they are out of alignment?


    Would be interesting to see what happens, if it places then back into the correct sequence or not.



    That's a thought, CCC the whole shebang to a external drive, option boot, erase the target completely in Disk Utiilty from the clone and reverse clone.


    CCC might fix it all without having to use Recovery HD or 10.6.



    If the Linux installer placed a swap folder in EFI, then that will have to be remedied or the last EFI folder deleted and twice reboot.



    fun fun fun.

  • Mr_Pie_Guy1234 Level 1 (5 points)

    Before I even installed Linux, I went to Disk Utility and made a swap and linux partition, so I don't think swap was put inside the efi. I also made sure that I put grub inside the linux partition, so when I booted linux through rEFIt, it would take me to grub.

  • Mr_Pie_Guy1234 Level 1 (5 points)

    So if I'm going to do all this, can I make a recovery usb off of the computer right now, erase the computer, then restore through a time machine backup?

  • Linc Davis Level 10 (192,206 points)

    You're replying to yourself, but I assume this was addressed to me. I don't know whether you can make a recovery device now, but it doesn't hurt to try. If it works, then the answer to the rest of the question is yes.


    It would be a good idea to have at least two independent backups before you partition the drive. Restoring to an empty drive is not a good time to find out that your only backup is corrupt.

  • Mr_Pie_Guy1234 Level 1 (5 points)

    Thanks for your help, I'm going to go on and give it a shot!

  • Linc Davis Level 10 (192,206 points)

    Just to be clear, you're going to install Lion first, and then restore your data from a backup in Setup Assistant.

  • Mr_Pie_Guy1234 Level 1 (5 points)

    Can't I just use a time machine backup to get everything on there at once?

  • Linc Davis Level 10 (192,206 points)

    You'll have to reinstall Lion anyway to get the recovery partition. You're less likely to have problems if you do that first, and then restore your other data.