windows keeps erasing boot flag

zowey · 03-02-2007, 08:46 AM

I read one topic about this problem and solution was something
like adding notice to windows that my linux paritition is active.
But in storage management i'm not able to set it active...
what shell i do?
Grub is installed, but windows changes flag to own parition so
grub can't say even word

pixellany · 03-02-2007, 09:50 AM

Linux does not use the "boot" or "active" flag. Set it on the Windows partition only.

zowey · 03-02-2007, 10:25 AM

WHy does it boots then?
I can't set anything active

pixellany · 03-04-2007, 08:09 AM

You can use any partition manager to set the active flag: fdisk, GParted (comes on a stand-alone live CD), QTParted (comes with many distros, including the Knoppix live CD)

The Linux bootloader (grub or lilo) sends the system to a specified partition--it does not care about the boot flag

zowey · 03-06-2007, 09:50 AM

even thought i put boot flag on linux, when i rise windows and reboot system it automaticaly goes to windows..
if i go to linux first and reboot the computer grub rises normaly.

osor · 03-06-2007, 10:52 AM

Quote:

Originally Posted by pixellany

Linux does not use the "boot" or "active" flag. Set it on the Windows partition only.

Unless linux’s bootloader is not in the MBR…

pixellany · 03-06-2007, 11:31 AM

Quote:

Originally Posted by osor

Unless linux’s bootloader is not in the MBR…

Are you saying that--if grub is in a partition boot sector and that partition is chain-loaded--that the active flag is required?

pixellany · 03-06-2007, 11:36 AM

Quote:

Originally Posted by zowey

even thought i put boot flag on linux, when i rise windows and reboot system it automaticaly goes to windows..
if i go to linux first and reboot the computer grub rises normaly.

I cannot visualize what you are doing. The computer will go the hard drive which the BIOS identifies as #1, and it will look in the mbr for boot code. ti does not matter how the active flags are set.

Windows does apparently need an active flag, but I am not sure at what stage of the process it matters.

What are you doing to "go to Linux first"?

Running from Linux, Please post the output of: (do these as root)

Code:

fdisk -l
cat /boot/grub/menu.lst

osor · 03-06-2007, 02:20 PM

Quote:

Originally Posted by pixellany

Are you saying that--if grub is in a partition boot sector and that partition is chain-loaded--that the active flag is required?

I’m saying if grub is on a primary partition’s volume boot sector, and the MBR has only the standard MS MBR code, and the aforementioned grub is desired to be chainloaded from the MBR, the corresponding partition should have the “active” flag set in the MBR’s partition table.

osor · 03-06-2007, 02:24 PM

Quote:

Originally Posted by pixellany

The computer will go the hard drive which the BIOS identifies as #1, and it will look in the mbr for boot code.

After it looks in the MBR for boot code, it will execute that code. If that code is standard PC MBR code (as opposed to grub or lilo code), that program will chainload the boot sector of the partition marked as active.

pixellany · 03-06-2007, 02:35 PM

Quote:

Originally Posted by osor

After it looks in the MBR for boot code, it will execute that code. If that code is standard PC MBR code (as opposed to grub or lilo code), that program will chainload the boot sector of the partition marked as active.

This would be a way of using the Windows mbr code to dual-boot Linux, n'est-ce pas?
Have you tried it? (I have never seen it mentioned in the bazillion of posts on dual-booting)

PS: Zowey; We have not forgotten you--we're just having a side discussion while waiting for some more info from you......

osor · 03-06-2007, 04:34 PM

Quote:

Originally Posted by pixellany

This would be a way of using the Windows mbr code to dual-boot Linux, n'est-ce pas?
Have you tried it? (I have never seen it mentioned in the bazillion of posts on dual-booting)

Yes I have (it has been).