On Mon, Mar 02, 2015 at 02:04:24AM +0000, Richard wrote:

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Date: Sunday, March 01, 2015 20:06:26 -0500 From: Fred Smith fredex@fcshome.stoneham.ma.us To: centos@centos.org Subject: [CentOS] installing C7 on a laptop with Win7, dual boot

Hi all!

I've just installed C7 on my netbook that already contained Win7 (and also Fedora 19, which the C7 is intended to replace). The Fedora installer had found the windows installation and it appeared in the grub menu, and was bootable and worked fine.

The C7 installer did not put the windows installation into the grub menu.

with some googling I found a page at https://priteshugrankar.wordpress.com/2014/09/12/dual-booting-cent os-7-and-windows-7/ that gives a simple recipe for fixing this problem. basically:

cp /boot/grub2/grub.cfg orig.grub.cfg grub2-mkconfig -o /boot/grub2/grub.cfg

with (on his system) the second command above producing this output:

[root@localhost ~]# grub2-mkconfig -o /boot/grub2/grub.cfg Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.16.2-1.el7.elrepo.x86_64 Found initrd image: /boot/initramfs-3.16.2-1.el7.elrepo.x86_64.img Found linux image: /boot/vmlinuz-3.10.0-123.el7.x86_64 Found initrd image: /boot/initramfs-3.10.0-123.el7.x86_64.img Found linux image: /boot/vmlinuz-3.10.0-123.6.3.el7.x86_64 Found initrd image: /boot/initramfs-3.10.0-123.6.3.el7.x86_64.img Found linux image: /boot/vmlinuz-0-rescue-327fe33f3b364802871211321a2790b7 Found initrd image: /boot/initramfs-0-rescue-327fe33f3b364802871211321a2790b7.img Found Windows 7 (loader) on /dev/sda1 Found Windows 7 (loader) on /dev/sda2 done

Unfortunately, when I did it, I got this:

Generating grub configuration file ... Found linux image: /boot/vmlinuz-3.10.0-123.el7.x86_64 Found initrd image: /boot/initramfs-3.10.0-123.el7.x86_64.img Found linux image: /boot/vmlinuz-3.10.0-123.20.1.el7.x86_64 Found initrd image: /boot/initramfs-3.10.0-123.20.1.el7.x86_64.img Found linux image: /boot/vmlinuz-0-rescue-c875112952114f6284f69abaa4f9a2f7 Found initrd image: /boot/initramfs-0-rescue-c875112952114f6284f69abaa4f9a2f7.img done

No mention of the windows installation.

It's not that I use the win7 installation much, but I do want to be able to do so when one of those rare occasions pops up.

Thanks in advance!

Fred

I too encountered this issue putting centos7 on a win7 machine. The solution is to:

edit:

/etc/grub.d/40_custom

putting in:

menuentry 'name' {

insmod ntfs

set root=(hd0,2)

chainloader +1

}

note: "name" can be anything you want (within reason), and is the name that will show in the boot menu.

So, I did this. I'm assuming that 'name' should be bare, with no quotes? well, I tried it both ways, makes no difference. The grub-mkconfig does not emit any lines about having found windows. its output looks the same as what I showed in the original mail, above.

there are 3 windows partitions, two of which appeared in grub previously. Here's the entry I made:

menuentry Win-7 { insmod ntfs set root=(hd0,1) chainloader +1 }

the values here:

root=(hd0,2)

will vary based on your disk setup. if you still have your fc19 grub/grub2 (whichever it used) configuration file you should be able to confirm the values from that.

I can still access the files (I made an image of the disk), but grub2 configurations are not human-readable, so I can't figure it out from that. however, if I look at the drive image with fdisk, it shows partition 2 as being bootable, so I used (hd0,1). maybe I s hould try (hd0,2) as an alternative...

when done, then:

grub2-mkconfig -o <output file>

personally, i didn't set the -o to the production grub.cfg file as my preference is to make backups and check things before potentially trashing a file like that, but do as you wish. when you're comfortable with the generated file move it to the production location and reboot.

- Richard

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