Re: How to safely switch grub booting in-place from one drive to a replacement with RAID?

[darrin . thomas]

Hi,

On 02/23/2017 08:03 AM, Andrei Borzenkov wrote:
>> I just want to be sure I understand what you mean by 'each disk'.
>>
>> Each Disk of the array?
>>
> 
> Correct.
> 
>> In my case that's
>>
>>    grub-install /dev/sdb
>>    grub-install /dev/sdc
>>
>> Or do you really mean
>>
>>> grub-install /dev/sda     <-------- the single, non-RAID disk
>>> grub-install /dev/sdb     <-------- only ONE disk of the array

> If you intend to remove sda and leave only sdb, sdc as the only drives -
> yes, but then it is more involved than that.

That's my goal - to end up with only /dev/md0 = /dev/sdb+/dev/sdc in place.  
/dev/sda will eventually go away.

> Could you run https://github.com/arvidjaar/bootinfoscript and make 
> RESULTS.txt available?

I'm swapping in a new power supply and case right now :-)  I'll get it posted 
as soon as it's back together and up and running again.

> Yes, grub2 supports all 1.x metadata variants.

Ok thanks.

>> I think that's done here on Opensuse with
>>
>> /boot/grub2/device.map

> No. device.map is almost always irrelevant for grub2 installation.
> Device for installation is stored in /etc/default/grub_installdevice;

Wow didn't know about that one!  Thanks for pointing it out.

> if you use YaST to configure bootloader and YaST detects that /boot/grub2
> is on RAID1 it should automatically configure system to install grub in
> MBR of both disks.

This time around trying to do it all from command line so I can understand 
what's going on without it all hidden behind a UI.

Thanks,

Darrin