LinuxQuestions.org - [SOLVED] Windows 10 / CentOS 7 will not dual boot

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Windows 10 / CentOS 7 will not dual boot

I installed Windows 10 first, then installed CentOS 7. I don't think CentOS overwrote the windows partition. But there is no option to boot windows. I have the option of booting centos, or centos.
I found no option to configure a bootloader during the centos installation.

would be nice to give us more details, like your partition information.

open a terminal and post the output of

Code:

sudo lsblk -f

cat /sys/firmware/efi

NAME FSTYPE LABEL UUID MOUNTPOINT
sda
├─sda1 ntfs System Reserved 02A4B917A4B90DE3
├─sda2 ntfs A62E4BB92E4B8173
├─sda3 xfs 249a2634-0644-4bd9-9ab8-8d3c25ae2c48
├─sda4
├─sda5 xfs e26c7c3e-3e7d-43ec-b46b-8bfe86572ed4 /boot
├─sda6 swap dc0e7787-1b7c-4270-845a-38e2037e781b
├─sda7 xfs root 5b00eae9-156b-4de6-be30-f60f676eef87 /
└─sda8 xfs 3e810b28-1a01-4520-84ba-56d83352dc1e /home

I cannot find an efi file.

cat /sys/firmware/efi
cat: /sys/firmware/efi: No such file or directory

$ ls -l /sys/firmware
total 0
drwxr-xr-x. 5 root root 0 Feb 13 15:03 acpi
drwxr-xr-x. 4 root root 0 Feb 13 20:03 dmi
drwxr-xr-x. 12 root root 0 Feb 13 20:03 memmap
drwxr-xr-x. 2 root root 0 Feb 13 20:27 qemu_fw_cfg

post

Code:

cat /etc/default/grub

# cat /etc/default/grub
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet"
GRUB_DISABLE_RECOVERY="true"

That looks like a MBR (aka MS-DOS) partition table. So non-UEFI, non-gpt - I didn't think retail versions of Win10 allowed that.

Check your firmware (i.e. BIOS) screens and make sure EFI mode is selected - not CSM (legacy) mode. Then erase the disk and re-install every thing again from scratch.

Quote:

Originally Posted by syg00 (Post 6329247)

OP already installed windows that way (I think). So it worked first. But OP will explain it.

Try this first,
add this to etc/default/grub

Code:

GRUB_DISABLE_OS_PROBER=false

Then run

Code:

sudo grub2-mkconfig -o /boot/grub2/grub.cfg

If this doesn’t work then will try manually adding a windows menuentry

> OP already installed windows that way (I think). So it worked first. But OP will explain it.

Yes, I originally installed windows, and windows booted and worked just fine.

would be nice to see the detailed info about those partitions (like size). Windows needs an efi partition, probably that's why it cannot be booted. What is sda4?

Quote:

That looks like a MBR (aka MS-DOS) partition table. So non-UEFI, non-gpt - I didn't think retail versions of Win10 allowed that

Yes windows 10 will install to a mbr partition table in non-uefi mode.

post the output of

Code:

sudo parted -l

Code:

# grub2-mkconfig -o / boot/grub2/grub.cfg

Generating grub configuration file ...

Found linux image: /boot/vmlinuz-3.10.0-1160.el7.x86_64

Found initrd image: /boot/initramfs-3.10.0-1160.el7.x86_64.img

Found linux image: /boot/vmlinuz-0-rescue-1495fd8baa4e4037ace10e1effc2d33a

Found initrd image: /boot/initramfs-0-rescue-1495fd8baa4e4037ace10e1effc2d33a.img

Found linux image: /boot/vmlinuz-0-rescue-f88f9bcae7074473912b27834c137add

Found initrd image: /boot/initramfs-0-rescue-f88f9bcae7074473912b27834c137add.img

/usr/sbin/grub2-mkconfig: line 290: /: Is a directory

Line 290: cat ${grub_cfg}.new > ${grub_cfg}

In context: (lines 279 to 293 of /usr/sbin/grub2-mkconfig):

Code:

if test "x${grub_cfg}" != "x" ; then

  if ! ${grub_script_check} ${grub_cfg}.new; then

    # TRANSLATORS: %s is replaced by filename

    gettext_printf "Syntax errors are detected in generated GRUB config file.

Ensure that there are no errors in /etc/default/grub

and /etc/grub.d/* files or please file a bug report with

%s file attached." "${grub_cfg}.new" >&2

    echo >&2

    exit 1

  else

    # none of the children aborted with error, install the new grub.cfg

    cat ${grub_cfg}.new > ${grub_cfg}

    rm -f ${grub_cfg}.new

  fi

fi

Quote:

Originally Posted by colorpurple21859 (Post 6329814)

Yes windows 10 will install to a mbr partition table in non-uefi mode.

post the output of

Code:

sudo parted -l

Code:

# parted -l

Model: ATA WDC WD10EZEX-22B (scsi)

Disk /dev/sda: 1000GB

Sector size (logical/physical): 512B/4096B

Partition Table: msdos

Disk Flags: 



Number  Start  End    Size    Type      File system    Flags

 1      1049kB  525MB  524MB  primary  ntfs            boot

 2      525MB  105GB  104GB  primary  ntfs

 3      105GB  106GB  1074MB  primary  xfs

 4      106GB  1000GB  894GB  extended

 5      106GB  107GB  1074MB  logical  xfs

 6      107GB  113GB  6041MB  logical  linux-swap(v1)

 7      113GB  167GB  53.7GB  logical  xfs

 8      167GB  1000GB  833GB  logical  xfs

Maybe I would do better with something more recent? Rocky Linux, Oracle Linux, Fedora, or Stream CentOS?