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-   -   Software RAID 1 setup on CentOS using Grub boot loader (

kumarsundaram 11-29-2005 07:39 PM

Software RAID 1 setup on CentOS using Grub boot loader
Hello All,
I am trying to setup a RAID 1 on my system that has 2 identical IDE hard disks. I am installing CentOS 4.2 x64 and doing a software RAID.

This is what my partitioning look like:

/dev/md1 2000MB Swap
/dev/md2 76096MB ext3 /
hda1 196MB ext3 /boot
hda2 76096MB SoftwareRaid
hda3 2000MB SoftwareRaid
hdb1 196MB ext3 /boot2
hdb2 76096MB SoftwareRaid
hdb3 2000MB SoftwareRaid

Okay... When I was googling for help I read on a site that it is not recommended (or not possible, I can't remember now) to create a mirror of the /boot partition. So, that's why I created /boot on my hda1 and had to call it /boot2 on my hdb1 (some temporary name I picked) - originally I had them mirrored and it was called /dev/md0 and I installed centOS and wasn't able to boot successfully. Therefore, I removed the mirroring on those two partitions for now.

Anyways, during the installation(with the above RAID setup) I was given a choice of where to store the boot loader. My options were:
1) Install it on /dev/hda Master Boot Record
2)First sector (or similar wording) of /dev/hda1

I chose the second option /dev/hda1 - Idea was to store the boot record on this partition now and figure out a way to mirror it to my other drive (hdb1 or /boot2).

So, I was hoping that the system should boot normally after the installation with the current setup I have shown above.

Unfortunately, when it booted I see the word Grub and there is a hypen (-) next to that word just flashing... Nothing else is happening.

I need some help!! Could someone please explain to me whether the RAID setup I have is valid?? If so, how can I get the system booted?

If my setup is wrong.. could you please recommend what I should be doing??

Basically, I want a complete RAID 1 setup so if one of my hard disk fails the other one will take over and during a disaster if I have to reboot the system for any reason I want it to be able to boot normaly from the second hard disk upon the failure of the first one.

Any help??? Thanks in advance.

blkcamarozr28 11-30-2005 12:57 PM

Use your CentOS CD1 and boot into Linuxrescue. From there you can fix your master boot record.


grub>root (hd0,0) ***Sets mbr on both hdd's
grub>setup (hd0)
grub>root (hd1,0)
grub>setup (hd1)

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