Dual Booting with raid

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legit · Post by **legit** » Sat Mar 13, 2010 12:30 pm

Hello,

So I've never done raid before, I plan to setup my new computer (in the bios) with raid 1 (mirroring) and dual boot gentoo with windows 7.

With windows I have to create a special "boot disk" (on a usb flash drive).

Is there any thing special I need to do for installing gentoo?

Post by **NeddySeagoon** » Sat Mar 13, 2010 2:07 pm

legit,

As you set up the raid in the BIOS, you are using device mapper raid - dmraid for short.
If your root filesystem will be on the raid volume, you need an initrd including dmraid to provide access to the raid, so the kernel can mount its root.

genkernel can build you such an initrd.

legit · Post by **legit** » Sat Mar 13, 2010 3:50 pm

If I don't want to do a genkernel?

r3tep · Post by **r3tep** » Sat Mar 13, 2010 4:24 pm

Then you'll have to create the initrd by hand.

Unfortunately, you'll have to recreate the initrd every time you change something on your kernel.

legit · Post by **legit** » Sat Mar 13, 2010 4:25 pm

So it looks like I just have to install the correct drivers in the kernel for it if I build the kernel myself.

At least according to the gentoo wiki: http://en.gentoo-wiki.com/wiki/RAID/NVRAID_with_dmraid

Can someone verify that for me, I'm not sure how much to trust the gentoo-wiki these days, ever since its crash it's seemed a bit out of date.

r3tep · Post by **r3tep** » Sat Mar 13, 2010 4:47 pm

If you want to boot from that RAID, you'll have to create the initrd http://en.gentoo-wiki.com/wiki/RAID/NVR ... l_RAM_Disk

If you have a running system and you only want to add a RAID, you'll need only these drivers.

The third way, described in the wiki as "using a self-built kernel", describes how to add the self-built kernel to an initrd you have to create.

legit · Post by **legit** » Mon Mar 15, 2010 10:46 pm

so I've decided to do a genkernel, will this guide be all I need to do?

http://en.gentoo-wiki.com/wiki/RAID/Onboard

ndse2112 · Post by **ndse2112** » Tue Mar 16, 2010 12:45 am

you can use genkernel to just build the initrd, just make sure that you have support in your kernel.

eg:

Code: Select all

genkernel --luks --lvm --dmraid --kernel-config=/usr/src/linux/.config initramfs

Yamakuzure · Post by **Yamakuzure** » Tue Mar 16, 2010 10:13 am

legit wrote:With windows I have to create a special "boot disk" (on a usb flash drive).

I have Windows 7 and Gentoo on a Computer dualbooting that uses a stripeset with 4 HDs. And I do not need a special boot disk, just grub. And Neither windows vista nor windows 7 needed a special disk for the installation either. I really hope that that is true for you, too.

paultrinity09 · Post by **paultrinity09** » Tue Mar 16, 2010 2:07 pm

Thanks a lot for share\ing this been wondering how to create dual boot.

legit · Post by **legit** » Tue Mar 16, 2010 9:19 pm

ok, so let me make sure how to do this correctly.

I run genkernel to install the initramfs

Code: Select all

genkernel --dmraid --install --kernel-config=/root/kernel-config initramfs

Then I can install a custom built kernel in the normal fashion, making sure that I include support for dmraid?

is that correct?

OR...

I could just do a genkernel with dmraid and not worry about anything else right?

ALSO...

If i do a genkernel for the initramfs, and a custom kernel. then everytime I upgrade my kernel I have to repeat the steps of generating an initramfs with the genkernel right?

I'm getting kind of confused between all the different methods.

Dual Booting with raid

Dual Booting with raid

Re: Dual Booting with raid