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Thread: Can't boot from HD, DVD no problem (Secure Boot?)

  1. #1
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    Default Can't boot from HD, DVD no problem (Secure Boot?)

    I have a problem that can be described similarly as the OP of this thread, though the situation seems to be different somewhat, hence my reason for posting a new thread. The situation is as follows:

    I've purchased a new system on which I want to run openSUSE 13.1. The system is manufactured by Acer and is a Aspire TC-603. It's not a laptop but a tower model. It came pre-installed with Windows 8 so I expected Secure Boot to be present and sure enough, it is. I didn't want to dual boot the system because I don't use Windows so I set about looking for ways to completely disable Secure Boot so I could install openSUSE unmolested. Acer was helpful enough to provide the following way to turn off Secure Boot in the BIOS: Windows 8 Desktops - How to disable Secure Boot.
    I followed those instructions and following that, I could boot from the install DVD and access the installer.

    I proceeded to use the installer to completely repartition the disk to suit my needs, removing all partitions present. I set up encrypted partitions for the areas that can/will hold data. I then went through the installer and pretty much accepted all the defaults. OpenSUSE installed without complaints or problems and rebooted as is normal. However, the system appears to be unable to find Grub2. The system sits there only showing a cursor flashing in the top left position of the screen.
    Booting from the install DVD works though and if I select the option there to boot from HD, openSUSE start normally and I can work with the system.

    My question is: what step have I missed or where did I go wrong to enable booting from the HD? More importantly, is there a fix that I can use without having to install openSUSE again?

    Here is the output from parted for the disk concerned.

    Code:
    # parted -l
    Model: ATA ST1000DM003-1CH1 (scsi)
    Disk /dev/sda: 1000GB
    Sector size (logical/physical): 512B/4096B
    Partition Table: gpt
    
    Number  Start   End     Size    File system  Name     Flags
     1      735MB   2887MB  2152MB               primary
     2      2887MB  35.1GB  32.2GB  ext4         primary  boot, legacy_boot
     3      35.1GB  45.8GB  10.7GB               primary
     4      45.8GB  56.6GB  10.7GB               primary
     5      56.6GB  1000GB  944GB                primary

  2. #2
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    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    Yesterday, I did a complete reinstall of openSUSE 13.1 to the system. This time, I created a separate boot partition on the disk to see if that would help the BIOS to find the boot loader. However, no such luck. When booting from the HD, the system prompts me to insert bootable media in the specified drive. Booting from the install DVD still works though and allows me to boot from the hard disk.

    CSM is enabled in the BIOS, Secure Boot is disabled. Grub2 is installed and set not to boot from MBR but to boot from partition, as is the default.
    Do I need grub2-efi instead of grub2 if CSM is enabled?

  3. #3
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    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    No, I don't think that combination can boot.

    You obviously have done what Acer's instruction video told you to, but the video actually tells you to do more than just disable SecureBoot: You are also instructed to disable UEFI (you do that by enabling CSM).

    That would have been fine, had you also _fully_ repartitioned your harddisk pending your enabling CSM, but you didn't (yes, I agree - it is not too obvious, but you need to wipe the partition table to switch from GPT to MBR). Remnants of GPT partitioning were left on the disk, so when installing OpenSuse, it installed according to what it found on the disk: A GPT partition. CSM, however, is looking for an MBR partition. (Yes, GPT has a protective MBR partition, so a hybrid is possible, but that has to be tailored using e.g. gdisk - which I have never done).

    I see three ways to resolve this, each having its own set of assets and drawbacks. Other members in these forums may have other ideas as well:
    • Go back and disable CSM i your BIOS (but leave SecureBoot disabled). That would leave you in a pure UEFI/GPT environment, which in my view is sensible, as MBR cannot cope with disks > 2TiB (approx. 2.2TB) in size. Also, GPT partitioning is easier than MBR as everything are primary partitions, and you can have virtually any number of them (in chunks of 128). You may need a fresh installation *) of openSUSE, since it was installed for another BIOS configuration than what you now enabled. It doesn't take long to try without a reinstallation, though.
    • Keep you BIOS setup as-is and wipe your disk completely clean and do a reinstall. This would enable good-old MBR, and will limit your disk size to 2TiB. When you add more disks in your setup, it may be possible that a mix of MBR partitioned and GPT partitioned disks will work, though. You will want GPT some time in the future to cope with large disks, and I don't think it matters if you connect external disks over USB. I haven't tested that, however, nor have I studied any documentation in that particular respect. But it is my understanding as of now. Others need to supply info here, or you look it up/test it for yourself.

    A disk-wiping command to be used for wiping your disk's partition table can be (to be run as root)
    Code:
    su -
    gdisk /dev/sda
    z
    w
    NOTE: THIS WILL DESTROY ALL DATA ON YOUR DISK! You can see http://rodsbooks.com/gdisk/gdisk.html for more info on gdisk.

    • Again, using gdisk, enable the hybrid MBR/GPT partition table (see the link above). This will also need a reinstall *), since an MBR-boot must be enabled.


    *) It is possible (I'm guessing here, but I would look into it - as reinstalling grub isn't very time consuming) that you can do a grub reinstall, and that is all that needs to be done. The rest of your installation is probably ok. The same may even be true for the uppermost alternative, as grub takes care of loading linux (=the booting process), and that is what you are struggling with. See https://forums.opensuse.org/content....rom-DVD-Rescue for a way to do that.


    Note: If you choose to try and reinstall Grub as in the link provided, you should note that
    Code:
    mount /proc
    mount /sys
    is probably not needed for openSUSE 13.1 (see comments in the the link of Jan 13th and 14th 2014). However, if you need them, you will need do enter them in the following way:
    Code:
    mount --bind /proc /mnt/proc
    mount --bind /sys /mnt/sys
    Give it a try and see how it works.


    Good luck!

    dayfinger

  4. #4
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    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    Hey dayfinger,

    First and foremost: many thanks for your elaborate reply. I *think* I understand most of it but I would just like to clarify one point, if I may.
    You mention the following:
    That would have been fine, had you also _fully_ repartitioned your harddisk pending your enabling CSM, but you didn't (yes, I agree - it is not too obvious, but you need to wipe the partition table to switch from GPT to MBR). Remnants of GPT partitioning were left on the disk, so when installing OpenSuse, it installed according to what it found on the disk: A GPT partition. CSM, however, is looking for an MBR partition.
    I was under the impression that I had fully repartitioned my disk as follows:
    I proceeded to use the installer to completely repartition the disk to suit my needs, removing all partitions present.
    My question is: am I wrong in assuming that this would also _completely_ wipe the partition table on the disk?

    For the moment, I'm going to assume I was wrong and am looking with interest to option 1, and then trying to reinstall Grub, to see if that clears things up. If not, it's not a problem to reinstall the system from scratch.

    Again, many thanks!

  5. #5
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    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    You are welcome.

    Quote Originally Posted by joopberis View Post
    ....Hey dayfinger,

    First and foremost: many thanks for your elaborate reply. I *think* I understand most of it but I would just like to clarify one point, if I may.
    You mention the following:


    I was under the impression that I had fully repartitioned my disk as follows:

    My question is: am I wrong in assuming that this would also _completely_ wipe the partition table on the disk?

    For the moment, I'm going to assume I was wrong and am looking with interest to option 1, and then trying to reinstall Grub, to see if that clears things up. If not, it's not a problem to reinstall the system from scratch.

    Again, many thanks!
    Yes - that is where you were wrong. As I said, it is not obvious. The "problem" is that in a GPT partitioning scheme, the GPT partition table is preceeded by an MBR partition table dubbed "Protective MBR table". That construction makes a lot of sense for the coming years when the world will make the move from MBR to GPT: None of the old MBR partitioning tools knows anything about GPT, and they are all able to create an MBR table. If there is no MBR table, these tools consideres such a disk as unpartitioned and will overwrite whatever being present - maybe even without warning since the disk (wrongly) would be known to be empty. Thus, an MBR table is written prior to the GPT table to protect the GPT table from these tools.

    Modern disk partitioning tools, being GPT aware, needs to see the GPT table following the ("protective") MBR table to identify a GPT partitioned disk.

    ---

    So, when you were go back from UEFI (which knows about GPT partitions) to CMS (which knows nothing about GPT), the BIOS will locate the protective MBR table and be happy with that. The GPT partition table (which is still there as you have not removed it) will sit there silently, doing nothing. The protective MBR will point to the first 4 partitions on the disk that is within 2TiB addressing. How the tiny details work out when you break that 2TiB limit, I do not know.

    Actually, this happens because the partitioning tool you use from openSUSE 13.1 do know about GPT, and handles it properly. (These tools cannot automatically wipe the GPT partition table just because CMS is in effect as there is no technical reason that stops CMS/BIOS to use GPT as well, except that such support needs to be implemented at some level - even if such implementation is a manual one).


    Thus, in order to go back from GPT to MBR partitioning, you need to physically erase/wipe both the (protective) MBR partition table and the GPT partition table so the old tools can start afresh, and the openSUSE installation procedure (that knows both GPT and pure MBR setups) doesn't get confused by the GPT table following the MBR table. After wiping both tables, disk partitioning tools will default to MBR-only partitioning when used under CMS mode, and properly create an old-fashioned MBR setup during disk partitioning.


    Good luck!


    dayfinger

  6. #6
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    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    Quote Originally Posted by dayfinger View Post
    Yes - that is where you were wrong. As I said, it is not obvious. The "problem" is that in a GPT partitioning scheme, the GPT partition table is preceeded by an MBR partition table dubbed "Protective MBR table". That construction makes a lot of sense for the coming years when the world will make the move from MBR to GPT: None of the old MBR partitioning tools knows anything about GPT, and they are all able to create an MBR table. If there is no MBR table, these tools consideres such a disk as unpartitioned and will overwrite whatever being present - maybe even without warning since the disk (wrongly) would be known to be empty. Thus, an MBR table is written prior to the GPT table to protect the GPT table from these tools.

    Modern disk partitioning tools, being GPT aware, needs to see the GPT table following the ("protective") MBR table to identify a GPT partitioned disk.
    Thanks again. This actually clarifies a lot because I had real trouble understanding why it wouldn't boot, despite setting CMS enabled in the BIOS and repartitioning the disk. I've been reading up on UEFI, GPT and Secure Boot but I've not yet seen it explained as clearly and succinctly as you have done here in terms of disk structure.

  7. #7
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    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    Just a quick update.

    It appears that Acer is a bit odd, when it comes to booting with CSM disabled and Secure Boot also disabled.

    I went for dayfinger's option 1, which was:
    Go back and disable CSM in your BIOS (but leave SecureBoot disabled).
    When I do that, the system will not boot from DVD, even if the first boot device is set to CD/DVD in the BIOS. All it does is ignore the boot device I set and attempts to boot from the HD anyway, which causes it to casually inform me:

    Code:
    Reboot and select proper Boot Device.
    or Insert Boot Media in selected device and press a key
    It appears that Acer *requires* CSM to be enabled in order to boot from anything besides the HD, as also mentioned here: http://www.mysysadmintips.com/windows/simple-how-tos/422-acer-xc600-how-to-boot-from-cd

    It appears that tougher measures are needed to get openSUSE to boot normally, like I intended. I'll be looking into gdisk next.

  8. #8

    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    Hi !

    Quote Originally Posted by joopberis View Post
    Just a quick update.
    It appears that Acer is a bit odd, when it comes to booting with CSM disabled and Secure Boot also disabled.
    With both CSM and Secure Boot disabled, you should be booting in 'plain' UEFI mode,
    which should in general work with the openSUSE DVD.

    Can you make sure that you actually boot in UEFI mode in that case?
    (should hopefully be obvious from the boot options of your BIOS).

    On the other hand you could well partition your hard disk the old style (using MBR)
    and boot the system using CSM, if the size of your hard disk is 2 TB or less.
    What's the size of your hard disk?

    However, there are further restrictions then, with respect to the maximum number (4 as far as I remember)
    of primary partitions on that hard disk.

    Good luck
    Mike

  9. #9

    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    Oops missed you 1st post.

    Your hard disk has size 1TB.

  10. #10

    Default Re: Can't boot from HD, DVD no problem (Secure Boot?)

    OK, to get your PC running I suggest the following:

    Turn on CSM again using your BIOS.

    Then boot from the DVD (which should again work then).

    Install openSUSE.

    OpenSUSE should then boot from hard disk as well.

    If you would like to provide for more then one root and more than one home partition,
    or if you would like to provide for dual-booting with other OSs in the future, ask.

    Good luck
    Mike

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