is it possible to boot into linux from this setup?

savager1 · 12-04-2007, 06:30 AM

Hello,

I have the following setup:

2x 400GB SATA Seagate Barra's in RAID0 & 1x 500GB SATA Seagate Barra

I currently have Windows XP installed on RAID0 array (that is the 2x 400GB drives) and I am wondering whether it's possible to install Linux of the third drive? See my problem is that I understand that Linux cannot write to ntfs partitions (I may not be 100% correct here as I know there is a ntfs-3g driver or something) but anyway I was wondering whether there is some way to boot to the third drive when I want to use Linux. When I was first building the PC I just tested things out by installing GRUB onto the MBR which of course damaged my Windows XP install.

So, in summary my question is: Is it possible to boot into the third drive (where I will install Linux)? even if there is a method of putting some kind of boot CD in that can allow me to select the third drive somehow?
(If it is possible please post some detailed instructions and please also let me know whether I need to install GRUB or not on third drive)

Thanks in advance

jschiwal · 12-04-2007, 07:33 AM

Yes. Grub can boot from a third drive as easily as another partition on the first drive, or a second drive. You can also install grub to the mbr of the third drive and use the Windows boot loader to boot Linux as well. ( Search this site for instructions or use Google for a search of "NT Grub boot how to". XP uses the NT boot loader so the instructions are the same). The advantage here is that you aren't altering the MBR on the boot drive. You need to copy a short (255 byte) image of the mbr from the drive or partition you installed the grub boot loader on, and edit the windows C:/BOOT.INI system file.

On many computers you can press a key to select a boot menu. This would allow you to select the Linux drive to boot from the BIOS menu (if you used the the third drive's mbr to install the grub boot loader).

tagno25 · 12-04-2007, 07:38 AM

Quote:

Originally Posted by savager1

Hello,
I currently have Windows XP installed on RAID0 array (that is the 2x 400GB drives) and I am wondering whether it's possible to install Linux of the third drive? See my problem is that I understand that Linux cannot write to ntfs partitions (I may not be 100% correct here as I know there is a ntfs-3g driver or something) but anyway I was wondering whether there is some way to boot to the third drive when I want to use Linux. When I was first building the PC I just tested things out by installing GRUB onto the MBR which of course damaged my Windows XP install.

NTFS-3G allows to read and write to NTFS partitions.

grub on the MBR didnot damage the windows partition you just have to fix the windows boot loader by booting the recovery console with the CD and running fixmbr

http://www.microsoft.com/resources/d....mspx?mfr=true

Quote:

Originally Posted by savager1

So, in summary my question is: Is it possible to boot into the third drive (where I will install Linux)? even if there is a method of putting some kind of boot CD in that can allow me to select the third drive somehow?
(If it is possible please post some detailed instructions and please also let me know whether I need to install GRUB or not on third drive)

yes, it is possible, you need to install GRUB or LILO onto the main mbr and then fix the XP boot record

savager1 · 12-04-2007, 08:17 AM

Quote:

Originally Posted by tagno25

yes, it is possible, you need to install GRUB or LILO onto the main mbr and then fix the XP boot record

so just to make sure I understand what you mean...you mean to install GRUB onto the main MBR (even though there is RAID0 array running winxp and running ntfs). Then once I have installed Linux onto the third drive and GRUB onto main MBR (raid0 array running xp in ntfs [won't Linux choke as it's ntfs?]), then how do I go about fixing up XP boot record? (could you please give basic direction?)

Thanks...sorry for the newbish question

tagno25 · 12-04-2007, 09:18 AM

do what jschiwal says to do it should be easier on a system that has RAID(software?)

jschiwal · 12-04-2007, 09:30 PM

There is a "Grub Raid Boot How To", but it deals with Linux raid using raid1 (mirroring). Grub is installed to the first device making up the mirrored array. Once the kernel is loaded it detects the raid array and creates the md# devices. In your case you are using striping instead. I think the problem you have is that grub can't handle the raid0 array and so the NTLDR program isn't run when you selected Windows. Look in the Linux /boot partition. There may be a backup of the original MBR. Restoring it might bring things back to normal. However, I don't know in your case where the mbr came from; the first disk, or from the striped array. If the partitioning table is valid on the raid devices, make sure that you only restore the first 446 bytes.

Code:

dd if=/boot/mbr_backup bs=446 count=0 of=/dev/sda (for the disk)
or
dd if=/boot/mbr_backup bs=446 count=0 of=/dev/md0 (for the raid array if it is detected in Linux)

Again, I don't know which device contains the mbr on a Windows Raid0 drive. Some more research may be needed. Running the fixmbr program may be a the best option, but will the Windows rescue console understand a raid array either?

When I used RAID for a time on my desktop, I didn't use the onboard raid for Linux. It was software raid anyway. I created an initial 60MB partition on both drives but used them normally. On first disk I installed /boot. On second drive, I simply copied all of the /boot/ files as a backup. This way I could boot normally. The kernel and initrd could load from a normal partition. After that the kernel was running with the modules loaded that could recognize and assemble the raid array.

I hope that you realize that using raid0, you double the chance of failure. A failure in one drive will result in the failure of the array.
--

Here is a howto to use NTLDR to boot linux: http://www.geocities.com/epark/linux...w2k-HOWTO.html
You might consider installing Linux to the mbr of the third drive instead of the /boot partition. That would allow you to boot up be selecting the third drive in the BIOS boot menu.

references:
boot.ini from above link:

Code:

[boot loader]
timeout=5
default=multi(0)disk(0)rdisk(0)partition(1)\WINNT
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft Windows 2000 Professional" /fastdetect
c:\linux.bin="Linux"

Wiki article on the MBR:
http://en.wikipedia.org/wiki/Master_boot_record

savager1 · 12-04-2007, 11:00 PM

cool, thanks for all the replies.

I found a link to do the same thing in my distro:

http://docs.pclinuxos.com/Adding_PCL...ows_Bootloader

OK, so now I am getting error 21 with GRUB (now I have read up on this a bit and I know it means that the disk cannot be found...I believe)

So, I have this setup:

sda + sdb = RAID0 array running windows xp ntfs

sdc = linux

I installed PCLinuxOS onto sdc and also installed GRUB onto /dev/sdc and then copied bootsector as per the directions in above link to c:\ etc....

I have posted my menu.lst below: (I think that something could be wrong here...not sure though, could someone with a little more experience help me out here? To me something appears wrong with the hd0 numbering etc.)

timeout 10
color black/cyan yellow/cyan
gfxmenu (hd0,0)/usr/share/gfxboot/themes/pclinuxos/boot/message
default 0

title linux
kernel (hd0,0)/boot/vmlinuz BOOT_IMAGE=linux root=/dev/sdc1 acpi=on resume=/dev/sdc5 splash=silent vga=788
initrd (hd0,0)/boot/initrd.img

title linux-nonfb
kernel (hd0,0)/boot/vmlinuz BOOT_IMAGE=linux-nonfb root=/dev/sdc1 acpi=on resume=/dev/sdc5
initrd (hd0,0)/boot/initrd.img

title failsafe
kernel (hd0,0)/boot/vmlinuz BOOT_IMAGE=failsafe root=/dev/sdc1 failsafe acpi=on resume=/dev/sdc5
initrd (hd0,0)/boot/initrd.img

title windows
root (hd2,0)
map (0x82) (0x80)
map (0x80) (0x82)
makeactive
chainloader +1

Thanks in advance

jschiwal · 12-06-2007, 08:25 PM

When you boot up, do you see a windows boot menu with on entry for XP and another for Linux?

I think with your setup, you won't be able to boot into windows from the Grub menu, but you will be able to boot into Linux from the windows menu.

savager1 · 12-06-2007, 09:55 PM

thanks for all your help people...

but it was solved: Just had to go into bios and swap hard drive boot order to boot linux hard drive first.