Re: What will happen with spares in this scenario?

[Goswin von Brederlow <goswin-v-b@web.de>]

John McNulty <johnmcn1@googlemail.com> writes:

> On 30 Jun 2009, at 18:54, Goswin von Brederlow wrote:
>
>> In case of grub2: It does support both raid and lvm. The raid
>> superblocks are parsed to construct mdX devices and the lvm metadata
>> is parsed to locate lvm logical volumes. So you could say it does
>> construct the LV and mounts the FS.
>
> Interesting, thanks.  I've not been following grub2 development.
> Given the production nature of these systems though (and the customer)
> I'm stuck with grub legacy until Redhat update it and support grub2,
> which judging from the chatter on the Fedora Project Portal about the
> possibility of including it in Fedora 12, could be some years off.
> Looks like Ubuntu will be putting it into 9.10 though, so I'll have a
> play with it on one of my dev boxes at home.
>
>> In case of lilo: Lilo only stores a list of blocks where the
>> kernel/initrd are on the device. Afaik each component device of a raid
>> stores the the block numbers for the kernel/initrd on that component
>> device. So no matter which component device boots it will find the
>> kernel/initrd on the same device. The raid1 and lvm are completly
>> circumvented.
>
> Have not touched lilo since grub went main stream, but will have
> another look at that.
>
> I've gone over all this with the customer.  They want belt and braces
> protection (they are to be very critical systems in a hospital) so
> we've decided to hardware mirror c0d0 and c0d1 for the disks on one
> controller, plus the same for c1d0 and c1d1 on the second controller,
> then partition and md mirror both of those.  The rest of the disks
> will be handled separately and the kickstart config is quite simple.
> It's a bit overkill, but it won't be failing disks or controllers that
> cause the systems to fail in the future.
>
> Rgds,
>
> John

Don't worry, when you have a heart attack it won't be the disk that
fails. Some 0.1c diode ion the motherboard will burn through and take
out the system.

MfG
        Goswin