CentOS Win7 Dual boot on NVRaid (fakeraid)
 

Hello everyone,

For my project this weekend, I decided I would dual boot CentOS 5.6 and Windows 7 on my desktop. I have 2 500GB SATA drives, running in (fakeraid) RAID0 from the onboard Nvidia chip on the motherboard. I installed Windows 7 on a ~500GB partition first, everything went great. Next, I installed CentOS. I had 3 partitions, one for root (~300GB), one for swap (4GB), and a third for /usr (~200GB). The install went well, but when I restarted, I was still booting straight into Windows. At no time did I see a grub menu.

I booted from a live cd and reinstalled grub manually. But after I did that, the system would just boot to a grub prompt. I tried so many different things over the course of 6 hours, that I can't remember each of them. But as I tried manually configuring/installing grub, I would receive various errors from "File not found" to "stage1 not read correctly." At one point, I remember fdisk telling me "the number of cylinders for this disk is set to... larger than 1024." I eventually wondered if it was a problem with how I installed CentOS (since I'm usually an Ubuntu guy). So I put in my 10.04LTS CD and installed over the same partitions with Ubuntu. But at the end of the install, I kept receiving errors that grub couldn't be installed to /dev/sda. I kept pointing it to /dev/mapper/nvidia_XXXXXX, but it would just go back to trying /dev/sda.

Both CentOS and Ubuntu recognized the Raid configuration. Both of them were aware of the fact that the devices were mapped to /dev/mapper/nvidia_blahblahX. It's just as if grub wasn't yet able to access the partitions at that point of the boot process.

I ended up restoring the Windows 7 boot manager, so at least I'm back to square 1 now. But does anyone have any idea why I'm having so much trouble with this? Is what I'm wanting to do even possible?

Thank you in advance for your help.

did you take into account the "recovery" partition on sda1 that the OEM put there seeing as they do not give out win7 install dvd's
a default install of cent will put grub there

also with win7 it is best to let MS have the MBR ( Google this for more info)
and install grub on the FIRST linux partition ( ext3 for cent)
mark that as bootable and unmark the MS Windows MBR as bootable

1) repartition 50%-50% ( if that is what you want )
2) format the Linux half to ext3 for Cent -- rembor that RHEL/CentOS were DESIGNED for servers and not desktop
-- do not expect to play videos and music on Cent - you "can" but you run the risk of never booting Cent ever again ( a full reinstall to fix)
-- it is VERY VERY VERY easy to FUBAR rhel/cent with the rpm's from rpmforge & ATrpms so HEED EVERY WARNING IN THE WIKI !!!
http://wiki.centos.org/
http://wiki.centos.org/AdditionalResources/Repositories
3) reinstall win 7
4) install centOS 5.6 and use the installer gui to do a custom install of grub ( it is there LOOK it is hard to find)
the installer WILL ask if you want win7 ALSO bootable - say yes ( check other)

If grub can't access any part of the raid then it can't load up?

John,

Thank you very much for your reply. Your simple reminder about the system partition jogged my memory and helped me to fix the issue. I went ahead and reformatted the drive, taking care to place a boot partition at the beginning of the drive. I've not got Windows 7 and CentOS 5.6 installed. Thanks!

As far as CentOS goes, I'm not planning on using it for a desktop OS, but rather for development. At work, we do all of our development on CentOS and I've become the defacto "RPM guru," so I decided I should probably get myself a setup at home.

Thanks again for your help, I appreciate it!