Rhel 7 grub loader is not showing windows 7 entry

Latest response

Hi Experts,

I have installed RHEL 7 kernel 3.10.0-121 on my desktop pc for evaluation purpose.I have installed the OS on one single partition (/dev/sda4) for dual booting rhel with windows 7. However after installing rhel I am unable to find windows entry in grub loader and unable to boot windows 7. Tried to update grub2 loader by grub2-mkconfig command but no hope.

In fdisk command o/p, I am able to see 100mb ntfs boot partition and windows C drive partition,but not able to boot.

I am unable to find any useful resolution on web. Can any one help me on this..

Partition Details:

/dev/sda1 - 100MB windows
/dev/sda2 - windows c drive
/dev/sda3 - Extended Partition
/dev/sda4 - Rhel 7 Linux partition
/dev/sda5 - Extended windows partition

Responses

Windows co-existing with Linux on the same box using UEFI can be a bit tricky.

TL;DR - google search "rEFInd boot manager", install refind from your Linux partition, profit. I believe you will be working after installing/configuring refind.

I have not played around enough with RHEL 7 yet to know for certain what your layout should be. I was expecting to see an xfs partition for /boot. Could you provide the output from the following (or fdisk if parted complains)

parted /dev/sda print
fdisk -l

UEFI relies on the vfat partition which contains the bootloaders for the OS you would like to boot. Likely at this point, you could probably interrupt your boot process (at the BIOS/EFI level) and select the Boot Menu and Windows would be an option you can select.

You should see a /boot/efi/EFI directory from Linux

[root@cypher ~]# tree /boot/efi/EFI/
/boot/efi/EFI/
├── BOOT
│   ├── BOOTX64.EFI
│   └── fallback.efi
└── fedora
    ├── BOOT.CSV
    ├── fonts
    │   └── unicode.pf2
    ├── gcdx64.efi
    ├── grub.cfg
    ├── grubx64.efi
    ├── MokManager.efi
    ├── shim.efi
    └── shim-fedora.efi

Here is the drive layout on my system (the "Microsoft Basic Data" partitions are apparently not something to be alarmed about ;-)

Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 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
Disklabel type: gpt
Disk identifier: 0641F445-6B3E-434A-8E30-AA3937653395

Device           Start          End   Size Type
/dev/sda1         2048       411647   200M EFI System
/dev/sda2       411648      1435647   500M Microsoft basic data
/dev/sda3      1435648   1953523711 930.8G Microsoft basic data
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