[CentOS] CentOS 6.2 software raid 10 with LVM - Need help with degraded drive and only one MBR

[Jonathan Vomacka]

Essentially I guess the short question is, How do I make a non bootable 
drive bootable if the original MBR is no longer available?

On 3/2/2012 9:03 AM, Jonathan Vomacka wrote:
> CentOS Community,
>
> I have a dedicated server with 4 hard drives in a RAID 10 software
> configuration running LVM. My OS is CentOS 6.2. Earlier today, I
> rebooted my system and my system did not come back online. I opened a
> ticket with my datacenter who informed me that one of my hard drives is
> no longer recognized by the bios and has failed. I was told that an OS
> reinstall was needed.
>
> I don't understand why a reinstall would be necessary when the drives
> are in RAID 10. Apparently when the datacenter did the initial OS
> install, they ONLY installed the MBR on one drive instead of all 4
> leaving the other 3 drives unbootable.
>
> Is this a way to salvage this with a liveCD without having to reload the
> OS? This server is a very important mail server running OpenLDAP and
> MySQL. I figured maybe I could install the MBR using a liveCD which may
> fix the system.
>
> If an OS reload is the ONLY option, is there a way to reload it without
> touching the /var or /opt filesystems? (yes they were created as a
> seperate partition) however I am not sure if OpenLDAP or MySQL installs
> anything to /usr which I would be completely screwed...
>
> Please help