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  • Dual booting problem

    From Van Snyder@21:1/5 to All on Mon Jun 30 23:10:01 2025
    I'm working on an ASUS computer for a deceased colleague's widow.

    He had Fedora 28 on a HDD. I installed Debian 12 on an NVME drive. She
    also wanted Windoze 11 so I installed it on another NVME drive.

    The boot mode was set to "legacy" but the Windoze installer DVD
    wouldn't even boot until it was changed to "UEFI" and then the Debian
    DVD wouldn't boot in UEFI so I changed the boot mode to UEFI/Legacy.
    The Windoze drive has a FAT32 EFI partition.

    update-grub doesn't see the Windoze install. I manually added menuitems
    in /etc/grub.d/40_custom using the partition's UUID (search --fs-uuid)
    and the partition's label (search --fs-label). None of them work.
    During boot, grub says the boot file doesn't exist, but when I boot
    Debian and look in the Windoze EFI partition, it's there.

    The Fedora and Debian installs are non-EFI, so there's no EFI grub.

    I tried to add the Debian partition to the Windoze boot manager using
    bcdedit and easyBCD but neither one could see it.

    If I want to have dual boot, instead of telling the BIOS which
    partition to boot, must I essentially start over with the Debian
    install i EFI mode (if I can find an installer DVD that will boot EFI)?
    I don't want to muck with the Fedora install. If I get a Debian EFI
    install done, will its grub-update be able to see the Fedora
    installation?


    <html><head></head><body><div>I'm working on an ASUS computer for a deceased colleague's widow.</div><div><br></div><div>He had Fedora 28 on a HDD. I installed Debian 12 on an NVME drive. She also wanted Windoze 11 so I installed it on another NVME drive.
    </div><div><br></div><div>The boot mode was set to "legacy" but the Windoze installer DVD wouldn't even boot until it was changed to "UEFI" and then the Debian DVD wouldn't boot in UEFI so I changed the boot mode to UEFI/Legacy. The Windoze drive has a
    FAT32 EFI partition.</div><div><br></div><div>update-grub doesn't see the Windoze install. I manually added menuitems in /etc/grub.d/40_custom using the partition's UUID (search --fs-uuid) and the partition's label (search --fs-label). None of them work.
    During boot, grub says the boot file doesn't exist, but when I boot Debian and look in the Windoze EFI partition, it's there.</div><div><br></div><div>The Fedora and Debian installs are non-EFI, so there's no EFI grub.</div><div><br></div><div>I tried to
    add the Debian partition to the Windoze boot manager using bcdedit and easyBCD but neither one could see it.</div><div><br></div><div>If I want to have dual boot, instead of telling the BIOS which partition to boot, must I essentially start over with the
    Debian install i EFI mode (if I can find an installer DVD that will boot EFI)? I don't want to muck with the Fedora install. If I get a Debian EFI install done, will its grub-update be able to see the Fedora installation?</div><div><br></div><div><span></
    span></div></body></html>

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  • From Felix Miata@21:1/5 to All on Mon Jun 30 23:30:01 2025
    Van Snyder composed on 2025-06-30 13:59 (UTC-0700):

    If I want to have dual boot, instead of telling the BIOS which
    partition to boot, must I essentially start over with the Debian
    install i EFI mode (if I can find an installer DVD that will boot EFI)?
    I don't want to muck with the Fedora install. If I get a Debian EFI
    install done, will its grub-update be able to see the Fedora
    installation?

    Debian needs to be installed in UEFI mode for its Grub to be able to chain Win11's
    bootloader. Debian should have no problem loading Fedora's kernel and initrd via
    40_custom if necessary due to Fedora having been installed in legacy mode, if that
    was the case, or in UEFI mode but not using Grub, if that was the case. If Fedora
    was installed in UEFI mode with Grub, then Debian's os-prober should pick it up automatically, once os-prober is enabled, which would need to be changed from the
    "safe" disabled default (/etc/default/grub's GRUB_DISABLE_OS_PROBER="true").
    --
    Evolution as taught in public schools is, like religion,
    based on faith, not based on science.

    Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

    Felix Miata

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  • From Felix Miata@21:1/5 to All on Tue Jul 1 01:10:01 2025
    Van Snyder composed on 2025-06-30 14:46 (UTC-0700):

    On Mon, 2025-06-30 at 17:26 -0400, Felix Miata wrote:

    Debian needs to be installed in UEFI mode for its Grub to be able to>> chain Win11's
    bootloader.

    The netinst Debian 12 DVD I downloaded wouldn't boot in EFI mode. How
    do I install Debian 12 in EFI mode. Can I change it after it's
    installed?

    AFAIK, Debian doesn't make any installation .isos for Stable amd64 that will not
    boot in UEFI mode. What probably happened to you is one of two or more things:

    1-incomplete burning of .iso to USB media. Just because the burner program claims
    it's done doesn't necessarily mean the writing to the USB is complete. You must ensure the OS reports safe first. I ensure this by issuing the sync command after
    the write utility's claim of completion occurs. Only when sync returns is it sure
    to be truly safe to "safely" remove the device, or to reboot. As USB sticks are notoriously unreliable, I do my .iso writing to them using ddrescue instead of plain dd or any of the GUI tools designed for the task.

    2-you didn't try hard enough. One way to ensure you don't boot in CSM/legacy mode
    is to disable it in the UEFI BIOS. Another way to be sure is to use the BBS hotkey
    to select the boot device. UEFI capable media will normally show up in that menu
    (at least) twice, once with, and once without, a UEFI moniker. Simply select that
    which has a UEFI moniker included.

    3-USB3 sticks can't be expected to work properly in USB2 ports.

    If Fedora was installed in UEFI mode, you can use its bootloader to start a Debian
    installation by loading the linux and initrd.gz taken either from the NET installation media, or its mirrors counterpart: <http://ftp.us.debian.org/debian/dists/bookworm/main/installer-amd64/current/images/netboot/debian-installer/amd64/>

    Loading linux and initrd.gz with Grub is how most of my Linux installations begin.
    The following is (approximately) an EFI Grub2 stanza I previously used for the purpose:
    menuentry "Install Debian via HTTP" {
    search --no-floppy --label --set=root tm8p03res
    linuxefi /deb/linux showopts vga=791 --- net.ifnames=0 ipv6.disable=1
    netcfg/get_hostname=myhost netcfg/get_domain=mydomain.net netcfg/disable_autoconfig=true netcfg/get_ipaddress=192.168.###.###/24 netcfg/get_gateway=192.168.###.### netcfg/get_nameservers=1.0.0.1 netcfg/confirm_static=true tasks=standard base-installer/install-recommends=false
    GRUB_DISABLE_OS_PROBER=true
    initrdefi /deb/initrd.gz
    }
    Most of those linu line options are not necessary, but simply those I prefer be utilized to get a simple base installation working before adding selected non-essentials.
    --
    Evolution as taught in public schools is, like religion,
    based on faith, not based on science.

    Team OS/2 ** Reg. Linux User #211409 ** a11y rocks!

    Felix Miata

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    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Christensen@21:1/5 to David Christensen on Tue Jul 1 02:50:01 2025
    On 6/30/25 17:36, David Christensen wrote:
    +1 for multi-boot via multiple drives.


    Mobile racks facilitate changing drives:

    https://www.startech.com/en-us/hdd/mobile-racks

    https://www.startech.com/en-us/hdd/m2-removable-pcie-n1


    I should add -- only insert one bootable drive at a time. This
    eliminates the problem of OS updaters/ bootloaders stomping on each other.


    David

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Christensen@21:1/5 to Van Snyder on Tue Jul 1 02:40:02 2025
    On 6/30/25 13:59, Van Snyder wrote:
    I'm working on an ASUS computer for a deceased colleague's widow.

    He had Fedora 28 on a HDD. I installed Debian 12 on an NVME drive. She
    also wanted Windoze 11 so I installed it on another NVME drive.

    The boot mode was set to "legacy" but the Windoze installer DVD
    wouldn't even boot until it was changed to "UEFI" and then the Debian
    DVD wouldn't boot in UEFI so I changed the boot mode to UEFI/Legacy.
    The Windoze drive has a FAT32 EFI partition.

    update-grub doesn't see the Windoze install. I manually added menuitems
    in /etc/grub.d/40_custom using the partition's UUID (search --fs-uuid)
    and the partition's label (search --fs-label). None of them work.
    During boot, grub says the boot file doesn't exist, but when I boot
    Debian and look in the Windoze EFI partition, it's there.

    The Fedora and Debian installs are non-EFI, so there's no EFI grub.

    I tried to add the Debian partition to the Windoze boot manager using
    bcdedit and easyBCD but neither one could see it.

    If I want to have dual boot, instead of telling the BIOS which
    partition to boot, must I essentially start over with the Debian
    install i EFI mode (if I can find an installer DVD that will boot EFI)?
    I don't want to muck with the Fedora install. If I get a Debian EFI
    install done, will its grub-update be able to see the Fedora
    installation?


    +1 for multi-boot via multiple drives.


    Mobile racks facilitate changing drives:

    https://www.startech.com/en-us/hdd/mobile-racks

    https://www.startech.com/en-us/hdd/m2-removable-pcie-n1


    Keeping data on a file server or NAS allows you to access the data from whatever device or OS you are using. If the owner does not have/want
    such, put the data on dedicated drive(s) and use common-denominator
    techniques -- motherboard HBA/RAID, NTFS.


    David

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