Re: [PLUG] Fixing /boot/ too small

["Keith C. Perry via plug" <plug@lists.phillylinux.org>]

I would say this is a case of grub doing what we say and not what we mean...

What we really want is to install grub to the mirror volume (i.e. the thing analogous to the the physical disk).  Seems to me that should work or grub should have the knowledge to know that "oh this is mirror so let me install on all physical copies".  We're not going to be aware of any vg or lv util the system starts to boot and for that to happen, boot bits have to be on the physical drives.  Since I've never seen this documented, I'm assuming what actually happens is that the vg or lv actually would be corrupted.  I also don't think its documented anywhere that boot mirrors need to install grub to each physical disk for things to work properly if a mirror fails.

You're probably right that you don't have to reinstall since the grub.cfg will enable the mirror set during boot.  I've never worked out when exactly this need to be done so I just make it part of my procedure.  When I was running Slackware, I think I only ran LILO when there were kernel changes.

I'm not sure you "missed" anything per se.  There is just a bit of a disconnect between all these components because there has to be.

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Keith C. Perry, MS E.E. 
Managing Member, DAO Technologies LLC 
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www.daotechnologies.com

----- Original Message -----
From: "JP Vossen via plug" <plug@lists.phillylinux.org>
To: "Philadelphia Linux User's Group Discussion List" <plug@lists.phillylinux.org>
Sent: Sunday, June 28, 2020 3:35:22 PM
Subject: Re: [PLUG] Fixing /boot/ too small

On 6/28/20 3:21 PM, Keith C. Perry via plug wrote:
> Awesome JP !!
> 
> I could have sworn I mentioned that you had to do grub install to both mirror disks for true protection.  That has to be done even when you just use LVM to do your RAID 1.

You probably did and I probably *assumed* that `grub-update` would take 
care of it.  Any clue why it does not?  I mean, once you install GRUB 
it's installed, right?  So why do I need to reinstall it when I make a 
config change?  OK, it's a significant change, perhaps even a 
fundamental one...but it's still a config change.  And I never touched 
the start of /dev/sda or sdb.

And it's not like the old /boot/ was not on mdadm too, it was.  It's 
just that now /boot/ is on root on /dev/md1 instead of just being /boot/ 
on /dev/md0.  Clearly I seem to be missing something.

Later,
JP
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