Re: Installer - add BIOS boot partition?

[Cyril Brulebois]

Lennart Sorensen  (2019-01-14):
> Hmm, I recall having it give a checklist in the past, but I could be
> remembering wrong.
> 
> Certainly if I run dpkg-reconfigure grub-pc, it offers me a checklist
> of which devices to install grub on, so having both sda and sdb
> selected works fine.

If you go for a manual list, space-separated "/dev/sda /dev/sdb" works
just fine.

This is likely “grub-pc grub-pc/install_devices multiselect” in debconf
(but please double check!).

Checking grub2, this is very likely:

,---[ debian/grub-pc.templates.in ]---
| Template: grub-pc/install_devices
| Type: multiselect
| Choices-C: ${RAW_CHOICES}
| Choices: ${CHOICES}
| _Description: GRUB install devices:
|  The grub-pc package is being upgraded. This menu allows you to select which
|  devices you'd like grub-install to be automatically run for, if any.
|  .
|  Running grub-install automatically is recommended in most situations, to
|  prevent the installed GRUB core image from getting out of sync with GRUB
|  modules or grub.cfg.
|  .
|  If you're unsure which drive is designated as boot drive by your BIOS, it is
|  often a good idea to install GRUB to all of them.
|  .
|  Note: it is possible to install GRUB to partition boot records as well, and
|  some appropriate partitions are offered here. However, this forces GRUB to
|  use the blocklist mechanism, which makes it less reliable, and therefore is
|  not recommended.
`---


Cheers,
-- 
Cyril Brulebois (k...@debian.org)
D-I release manager -- Release team member -- Freelance Consultant


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Re: Installer - add BIOS boot partition?

[Lennart Sorensen]

On Sat, Jan 12, 2019 at 05:55:50PM +1300, Richard Hector wrote:
> Ok - as long as I remember to install to both. There's no option to
> install to both in one invocation, is there? Or a config file that
> records which drives are/might be used for booting?

Hmm, I recall having it give a checklist in the past, but I could be
remembering wrong.

Certainly if I run dpkg-reconfigure grub-pc, it offers me a checklist
of which devices to install grub on, so having both sda and sdb selected
works fine.

-- 
Len Sorensen

Re: Installer - add BIOS boot partition?

[Richard Hector]

On 12/01/19 3:44 AM, Lennart Sorensen wrote:
> On Fri, Jan 11, 2019 at 02:31:22PM +1300, Richard Hector wrote:
>> That worked great, thanks. Though it seems the '1.0MB' free before my
>> first partition wasn't big enough (or not aligned right?) so I had to
>> start from scratch.
>>
>> Incidentally, could/should I have made that RAID1? I created bios
>> partitions on both my disks, and have grub-install-ed to both. The
>> partitions do seem to be identical.
> 
> It might be possible to make it raid 1, although if you tell grub
> to install to both of them, that should work fine, and in fact you
> probably need that anyhow to get the bootstrap code into the MBR sector
> on both disks.  I think you are fine the way it is.  That partition is
> essentially an extension of the MBR sector for grub code so being per
> disk makes sense.

Ok - as long as I remember to install to both. There's no option to
install to both in one invocation, is there? Or a config file that
records which drives are/might be used for booting?

> And yes the partition tool won't let you create partitions that don't
> start on a 1MB alignment, so even though there was enough room for a
> partition there (of almost 1MB) it won't let you.  Not that loosing 1MB
> is a big deal.

1MB out of my 4TB disk? Come on, this is my money we're talking about :-)

>  Having to start over probably wasn't that big a deal
> either in this case.

True. I'd already missed the deadline for one backup run, and didn't
miss the next (this is the kvm host that my backup server runs on).

Thanks for all your help.

Cheers,
Richard

Re: Installer - add BIOS boot partition?

[Lennart Sorensen]

On Fri, Jan 11, 2019 at 02:31:22PM +1300, Richard Hector wrote:
> That worked great, thanks. Though it seems the '1.0MB' free before my
> first partition wasn't big enough (or not aligned right?) so I had to
> start from scratch.
> 
> Incidentally, could/should I have made that RAID1? I created bios
> partitions on both my disks, and have grub-install-ed to both. The
> partitions do seem to be identical.

It might be possible to make it raid 1, although if you tell grub
to install to both of them, that should work fine, and in fact you
probably need that anyhow to get the bootstrap code into the MBR sector
on both disks.  I think you are fine the way it is.  That partition is
essentially an extension of the MBR sector for grub code so being per
disk makes sense.

And yes the partition tool won't let you create partitions that don't
start on a 1MB alignment, so even though there was enough room for a
partition there (of almost 1MB) it won't let you.  Not that loosing 1MB
is a big deal.  Having to start over probably wasn't that big a deal
either in this case.

-- 
Len Sorensen

Re: Installer - add BIOS boot partition?

[Cyril Brulebois]

Hi Richard,

Richard Hector  (2019-01-11):
> That worked great, thanks. Though it seems the '1.0MB' free before my
> first partition wasn't big enough (or not aligned right?) so I had to
> start from scratch.

A size issue would be strange, at least given my recollection from
having checked that documentation a few months ago:
  https://www.gnu.org/software/grub/manual/grub/html_node/BIOS-installation.html

> Incidentally, could/should I have made that RAID1? I created bios
> partitions on both my disks, and have grub-install-ed to both. The
> partitions do seem to be identical.

AFAICT that's just some extra space that could be seen as extending the
MBR area, so that all bootloader bits fit. No need to make that kind of
things RAID1?


Cheers,
-- 
Cyril Brulebois (k...@debian.org)
D-I release manager -- Release team member -- Freelance Consultant


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Re: Installer - add BIOS boot partition?

[Richard Hector]

On 11/01/19 2:31 PM, Richard Hector wrote:

> Incidentally, could/should I have made that RAID1? I created bios
> partitions on both my disks, and have grub-install-ed to both. The
> partitions do seem to be identical.

I should clarify - I have 4 partitions on each drive:

bios
raid: /boot
raid: /
raid: lvm

... and I want to be able to recover easily if I have to replace the
boot drive, so I want the bios partition to be available and useful on both.

Thanks,
Richard

Re: Installer - add BIOS boot partition?

[Richard Hector]

On 11/01/19 6:52 AM, Lennart Sorensen wrote:
> On Thu, Jan 10, 2019 at 11:04:16PM +1300, Richard Hector wrote:
>> Hi all,
>>
>> I've just done most of an installation on a BIOS machine, with a pair of
>> new 4TB disks, which require GPT.
>>
>> Grub fails to install, which I possibly should have predicted - though I
>> thought di might have either coped or warned me.
>>
>> It seems I need a BIOS boot partition, and that it should fit in the
>> space before my first existing partition, is that right? Any tips on
>> creating such a thing, preferably from within the di environment?
>>
>> Or do I need to do some partitioning before starting the installer?
>> Links to relevant references or howtos welcome.
> 
> If you use guided partitioning the installer creates a 1MB partition
> with 'use as' set to 'Reserved BIOS boot area' which then shows as type
> 'biosgrub'.
> 
> So that would be the type to create yourself.
> 

That worked great, thanks. Though it seems the '1.0MB' free before my
first partition wasn't big enough (or not aligned right?) so I had to
start from scratch.

Incidentally, could/should I have made that RAID1? I created bios
partitions on both my disks, and have grub-install-ed to both. The
partitions do seem to be identical.

Thanks,
Richard

Re: Installer - add BIOS boot partition?

[Lennart Sorensen]

On Thu, Jan 10, 2019 at 11:04:16PM +1300, Richard Hector wrote:
> Hi all,
> 
> I've just done most of an installation on a BIOS machine, with a pair of
> new 4TB disks, which require GPT.
> 
> Grub fails to install, which I possibly should have predicted - though I
> thought di might have either coped or warned me.
> 
> It seems I need a BIOS boot partition, and that it should fit in the
> space before my first existing partition, is that right? Any tips on
> creating such a thing, preferably from within the di environment?
> 
> Or do I need to do some partitioning before starting the installer?
> Links to relevant references or howtos welcome.

If you use guided partitioning the installer creates a 1MB partition
with 'use as' set to 'Reserved BIOS boot area' which then shows as type
'biosgrub'.

So that would be the type to create yourself.

-- 
Len Sorensen

Installer - add BIOS boot partition?

[Richard Hector]

Hi all,

I've just done most of an installation on a BIOS machine, with a pair of
new 4TB disks, which require GPT.

Grub fails to install, which I possibly should have predicted - though I
thought di might have either coped or warned me.

It seems I need a BIOS boot partition, and that it should fit in the
space before my first existing partition, is that right? Any tips on
creating such a thing, preferably from within the di environment?

Or do I need to do some partitioning before starting the installer?
Links to relevant references or howtos welcome.

Thanks,
Richard