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Thread: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

  1. #1

    Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    My Asus G73S Quad-core computer with ubuntu 12.04 has become messed up after I added an external drive with a gpt partition table and an efi partition (4TB Seagate Backup+ Desk). I have disconnected that disk and am now attempting to convert my original 12.04 to an EFI boot. My computer has two disks sda for my ubuntu os and another that I am using for ntfs data created by my Virtualbox Windows 7 guest.

    I have tried boot-repair a few times and I am getting nowhere. I have a 64 bit liveusb that I am booting from and my original 12.04 is 64 bit as well.

    While booted from liveUSB in uefi I get the correct efi screen though when I run boot-repair I get the following error;
    "GPT detected. Please create a BIOS-Boot partition (>1MB, unformatted filesystem, bios_grub flag). This can be performed via tools such as Gparted. Then try again."

    Can you give me any advice as to how to get my EFI partition on my sda1 partion to work? http://paste.ubuntu.com/7253259/

    Thank you kindly for your time and consideration.

    Don

  2. #2
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    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    Only /dev/sda has a GPT (GUID partition table), not /dev/sdb, where you have Windows 7. This means as far as I understand, that windows 7 is installed in BIOS (or BIOS compatible or CSM) mode, because UEFI mode does not boot unless the drive has GPT.

    Many people would use UEFI only because the installation of Windows is in UEFI mode and 'forces' any other system in a dual boot setup to be in UEFI mode too. So in your case, I suggest that you do not bother to make the system work in UEFI mode.

    To boot from a GPT drive in BIOS mode, you need a small (1 GB) partition with the bios_grub flag (as you are told by Boot-Repair).

  3. #3
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    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    I have no idea if a Windows in Virtualbox in BIOS mode will work with Ubuntu in UEFI mode?

    But to boot with UEFI you need the drive to be gpt partitioned and an efi partition. The efi partition should be near beginning of drive, but some have had it further into drive and it worked.
    If drive is gpt partitioned you can boot in BIOS mode, but need the 1MB unformatted partition with the bios_grub flag.
    IF drive is MBR(msdos) you have to convert to gpt partitioning to use UEFI.

    How you install Ubuntu is based on how you boot installer UEFI or BIOS.

    But if you boot Boot-Repair in UEFI mode it will convert to UEFI mode or to BIOS mode if drive is gpt. If you manually installed to gpt without bios_grub then grub would not install and Boot-Repair would probably just offer BIOS update and then want the bios_grub partition.

    UEFI Windows issues
    [SOLVED] UEFI Virtualbox installation boot problem - Arch
    https://bbs.archlinux.org/viewtopic.php?pid=1231228
    Last edited by oldfred; April 15th, 2014 at 03:46 PM.
    For info on UEFI boot install & repair:
    http://ubuntuforums.org/showthread.php?t=2147295
    Please use Thread Tools above first post to close thread when/if answered completely.







  4. #4

    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    My system is not dual boot.Likely I may be facing an issue from when I originally removed Windows7, formatted, and installed Ubuntu, then installed windows as a Virtualbox VM. I only boot to Ubuntu 12.04 LTS. My sdb drive does contain my virtualbox virtual machines and shares for my virtual machines. In my case I bought an 4TB external drive for backups and when I used the included utility for that disk, Seagate 4tb Backup Plus Desk, from my Windows7 os that runs inside of Virtualbox, well, things got interesting because it has an EFI partition and will not get along with my Ubuntu installation.

    I am going to proceed with making my Ubuntu 12.04LTS uefi boot and I will take care of my Virtualbox installation afterward. Virtualbox likely won't be a problem to adjust.

    Thank you for your thoughts on my issue.

  5. #5

    Question Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    After much time and effort I believe that I may have found an issue that may be preventing my EFI partion from being detected.

    After running sudo fdisk -l I find that "Partition 1 does not start on physical sector boundary."

    After trying to align the partition with gdisk and no success I gave up and deleted the partition sda1 with gparted then rebooted to liveusb in uefi mode.

    After 2 reboots to Ubuntu 13.10 LiveUSB uefi mode the partition information remains in the protective mbr.

    sudo gdisk /dev/sda
    GPT fdisk (gdisk) version 0.8.7

    Partition table scan:
    MBR: protective
    BSD: not present
    APM: not present
    GPT: present

    Found valid GPT with protective MBR; using GPT.

    Command (? for help): ?
    b back up GPT data to a file
    c change a partition's name
    d delete a partition
    i show detailed information on a partition
    l list known partition types
    n add a new partition
    o create a new empty GUID partition table (GPT)
    p print the partition table
    q quit without saving changes
    r recovery and transformation options (experts only)
    s sort partitions
    t change a partition's type code
    v verify disk
    w write table to disk and exit
    x extra functionality (experts only)
    ? print this menu

    Command (? for help): p
    Disk /dev/sda: 1465149168 sectors, 698.6 GiB
    Logical sector size: 512 bytes
    Disk identifier (GUID): E38BF3D6-1462-4A68-9801-D3FDC4DAF176
    Partition table holds up to 128 entries
    First usable sector is 34, last usable sector is 1465149134
    Partitions will be aligned on 2048-sector boundaries
    Total free space is 1024747181 sectors (488.6 GiB)

    Number Start (sector) End (sector) Size Code Name
    2 616448 420046847 200.0 GiB 8300
    3 420046848 441018367 10.0 GiB 8200

    Command (? for help): q
    ubuntu@ubuntu:~$ sudo fdisk -l

    WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.


    Disk /dev/sda: 750.2 GB, 750156374016 bytes
    255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors
    Units = sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disk identifier: 0x00000000

    Device Boot Start End Blocks Id System
    /dev/sda1 1 1465149167 732574583+ ee GPT
    Partition 1 does not start on physical sector boundary.


    Aligning partions did not work for me.
    Deleting the problem partition not work for me.has not worked for me.



    It looks like I need to find a way to zap the protective mbr or rebuild it using the gpt table.



    How would you delete the protective mbr so that it no longer retains the deleted partition entry information?

  6. #6

    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    Also,

    sudo parted /dev/sda print | grep -i '^Partition Table'
    Partition Table: gpt

  7. #7
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    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    You do not use fdisk on gpt partitioned drives. It only has one gpt partition defined in the protective MBR. Gpt has the protective MBR so old partition tools see that drive is fully partitioned and do not damage drive.

    New partition tools all start first partition at sector 2048 and make sure every partition start is divisible by 8 for good alignment. You should not have to move partitions around and doing that to Windows NTFS partitions can cause major corruption.
    The reason for the alignment is new SSD and new hard drives with 4K sectors.
    First, understand that most partitioning tools have moved to a policy of aligning partitions on 1 MiB (2048-sector) boundaries as a way of improving performance with some types of arrays and some types of new hard disks (those with 4096-byte physical sectors). See article by srs5694:
    http://www.ibm.com/developerworks/li...-sector-disks/
    Post on 8-sector boundaries alignment by srs5694
    http://ubuntuforums.org/showthread.php?t=1685666
    it's 8-sector (4096-byte) alignment
    http://ubuntuforums.org/showthread.php?t=1768635

    What partition did you delete?
    It may start to be easier just to totally reinstall? You do have good backups of /home, list of installed apps and any hardware settings you may have changed in /etc?
    For info on UEFI boot install & repair:
    http://ubuntuforums.org/showthread.php?t=2147295
    Please use Thread Tools above first post to close thread when/if answered completely.







  8. #8

    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    I have backup images on a USB drive. I started chasing around an error on my sda drive that I cannot seem to get rid of. Clearly, fdisk -l causes a false flag of an error because I completely wiped the drive including GPT table & MBR then started to repartition to create an EFI partition that is aligned at 4096 or so I believe it is. I've lost much faith in the GUI tools because they all seem to give different values for the same partition.

    My new plan is to go with the EFI partition that I set up using gparted and then labeled and typed with gdisk. I am going to download a clean copy of Ubuntu 12.04LTS to a liveUSB and then I am going to reinstall, preferably in UEFI mode, using separate partitions for /boot, /home, & /tmp then I will figure out how to reintegrate my original home partition and packages after mounting my backup image. You could say I give up...lol.

    Here's a screen shot of the crazy partition values given in the various GUI tools. (made a mistake with a pointer arrow on the "disks" window, it should be more to the right)
    Last edited by don-handymanreality; April 16th, 2014 at 07:29 AM. Reason: mistake with one of my arrows on the image

  9. #9
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    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    You can attach screen shots with advanced editor and the paper clip icon at top of that editor..

    Generally better without /boot. That is required with LVM and full disk encryption and may be required with RAID or LVM. Rarely required with desktops and we regularly get users posting with full /boot partitions and then they have huge issues housecleaning. You still should houseclean /boot folder occasionally.
    I only have seen some with SSD have a separate /tmp and often those with lots of RAM mount it in RAM.

    For the Total space you want for Ubuntu:
    Ubuntu's standard install is just / (root) & swap, but it is better to add another partition for /home if allocating over 30GB.:
    Only if gpt - all partitions in gpt are primary:
    gpt: 300 MB efi FAT32 w/boot flag (for UEFI boot or future use for UEFI, you only can have one per drive, so if already existing do not attempt another)
    gpt: 1 MB No Format w/bios_grub flag (for BIOS boot not required for UEFI)
    for gpt(GUID) or MBR(msdos) partitioning
    Ubuntu partitions - smaller root only where hard drive space is limited.
    If total space less than about 30GB just use / not separate /home or standard install.
    1. 10-25 GB Mountpoint / primary or logical beginning ext4(or ext3)
    2. all but 2 GB Mountpoint /home logical beginning ext4(or ext3)
    3. 2 GB Mountpoint swap logical

    Depending on how much memory you have you may not absolutely need swap but having some is still recommended. I do not hibernate (boots fast enough for me) but if hibernating then you need swap equal to RAM in GiB not GB. And if dual booting with windows a shared NTFS partition is also recommended. But you usually cannot create that as part of the install, just leave some space. Or partition in advance (recommended).
    One advantage of partitioning in advance is that the installer will use the swap space to speed up the install. Thanks Herman for the tip.
    https://help.ubuntu.com/community/DiskSpace
    suggested partitions for just Ubuntu on 3TB drive.
    http://askubuntu.com/questions/33643...rtition-scheme
    Another advanced suggestion from TheFu with Multiple / (root) - Post #5 similar to what I actually do
    http://ubuntuforums.org/showthread.php?t=2170308
    http://ubuntuforums.org/showthread.php?t=2021534
    Last edited by oldfred; April 16th, 2014 at 03:34 PM.
    For info on UEFI boot install & repair:
    http://ubuntuforums.org/showthread.php?t=2147295
    Please use Thread Tools above first post to close thread when/if answered completely.







  10. #10

    Re: Converting ubuntu 12.04 bios boot to uefi boot, EFI partition not detected

    SWEET! Thank you oldfred! That is some great advice for setting up my new Ubuntu 12.04 install.

    After playing with Ubuntu 13.10 while attempting to restore my Ubuntu 12.04 I'm almost disappointed to go back to 12.04..lol. There is some really great work going on with 13.10. Ddrescue-gui and boot-repair are some fabulous tools to work with. boot-repair even upgraded my 12.04 installation for me and installed an efi signed kernel, AMAZING!

    oldfred, thank you for your time, consideration and great tips for my reinstallaion.

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