[clue-tech] md driver software raid and bootstrapping

[mike havlicek]

I suppose I could somewhat simulate the physical configuration changes
in the flash drive scenario by replacing a grubbed stick with a non grubbed stick. In a desktop system with IDE type drives I could disable a device in "Setup", but what can I expect with regards to things like autodetect, cable select, master, slave settings? 


-Mike


--- On Fri, 12/5/08, mike havlicek <mhavlicek1 at yahoo.com> wrote:

> From: mike havlicek <mhavlicek1 at yahoo.com>
> Subject: [clue-tech] md driver software raid and bootstrapping
> To: clue-tech at cluedenver.org
> Date: Friday, December 5, 2008, 10:49 AM
> Hello All,
> 
> Any suggestions on configuring drive mappings when
> mirroring a boot partition? In the scenario I am looking at
> I am using grub with ext3 on the mdX devices (md driver
> raid1). I am curious about the scenario where during a
> component failure, an unattended reboot is triggered before
> the failed component is replaced (which is most likely going
> to be the one where bootstrapping normally begins :).
> 
> I suppose that in whatever "mysterious" scanning
> that occurs, the method is
> not random, but BIOS specific --> undesirable
> experimentation? Or is there a general rule for getting the
> (hdx,y) grub representation and the linux representations
> (e.g. /dev/hdX) in cahoots
> 
> When experimenting with recovery scenarios using USB flash
> drives in a hub
> I expect that I encounter "mystery" that
> doesn't fairly represent IDE type
> drives. Hmm on that thought I wonder if it fairly
> represents a SCSI type array....Naw... USB flash drives are
> silly fun. What I have seen so far is that the mappings I am
> working with from the grub command line are different
> betweeb rescue mode on a particular distribution CD from
> what I see at the grub command prompt during a boot from a
> fresh install from the CD distribution from which that
> rescue boot came. I think this is without changing physical
> "drive" configuration. I probably just screwed
> something up .... This will require further observations.
> 
> I am not ready to start messing around with this on my
> server class systems
> anticipating that it will open up a new can of worms with
> system specific configuration utilities ... but perhaps the
> SCSI IDs will help bring some sanity... Normally I use
> hardware RAID, but given how low end my controllers are it
> might be worthwhile to compare the hardware and software
> based solutions...
> 
> 
> -Mike 
> 
> 
>       
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