[SOLVED] boot flag auto changing from partitions.

brunomoss · 08-05-2016, 12:04 PM

Dear Forum..

I installed Centos 6.8 as main OS to /dev/sda2 LVM
After that I installed Windows 10 to /dev/sda3 NTFS

Then I boot via live CD and fix grub and flag boot as /dev/sda1 back.

but what is happenin now is when I boot in Windows I cant boot in Centos again, so I boot in Livecd and checked that the boot flag is on /dev/sda3 again, I change back to /dev/sda1, but every time that I need to use windows this happens, theres any way to avoid that?thanks

MensaWater · 08-05-2016, 12:18 PM

Linux plays well with Windows but not vice-versa. It is always recommended to do you primary install of Windows first then do your Linux install.

brunomoss · 08-05-2016, 12:28 PM

Allright, thanks, so theres no way to fix that unless I install everything again?

rknichols · 08-05-2016, 05:09 PM

It sounds as though you installed GRUB in your Linux partition (sda1) instead of in the MBR (sda). From your live CD, just install GRUB in the MBR:

Code:

root (hd0,0)
setup (hd0)

Now you will always start out in GRUB. I suggest commenting out the "hiddenmenu" line in your GRUB configuration so that the menu will always be displayed and allow you to select which OS you want to boot. FYI, here are some lines from the grub.conf on my laptop, which boots CentOS, Windows 7, and Windows 10 (your partition numbers will be different):

Code:

default=saved
timeout=10
splashimage=(hd0,5)/grub/splash.xpm.gz
#hiddenmenu
title Microsoft Windows 7
	unhide (hd0,0)
	hide (hd0,3)
	rootnoverify (hd0,0)
	chainloader +1
	savedefault
title Microsoft Windows 10
	unhide (hd0,3)
        hide (hd0,0)
	rootnoverify (hd0,3)
	chainloader +1
	savedefault
title CentOS (2.6.32-642.3.1.el6.x86_64)
      	unhide (hd0,0)
	unhide (hd0,3)
	root (hd0,5)
	kernel /vmlinuz-2.6.32-642.3.1.el6.x86_64 ro root=/dev/mapper/luks-c58c3509-cec8-4f61-b2c5-a325fa65e416 crashkernel=auto rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 rd_LUKS_UUID=luks-c58c3509-cec8-4f61-b2c5-a325fa65e416 KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
	initrd /initramfs-2.6.32-642.3.1.el6.x86_64.img

Because I have two different Windows installations, I always keep the other one hidden from the one I am booting. Setting the boot default to the Windows version being booted allows Windows to reboot unattended when it insists on rebooting itself.

brunomoss · 08-07-2016, 09:29 AM

Thanks man.. I really installed that in /dev/sda1 instead of /dev/sda.
Now is working fine.
Thanks a lot...