[gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Howdy,

I'm installing Gentoo on another old box.  To be consistent I like to
use cgdisk, GPT I think it is called, to partition all my drives,
regardless of size.  Thing is, Grub works differently with GPT than it
does with the old DOS or whatever it is called, like fdisk does in the
old days.  I did some research but still find myself in some muddy
waters.  My take on some things I've read, I need a boot partition, not
to be confused with the /boot for kernels, init thingys and such.  Where
I get lost, most use gdisk.  I like cgdisk.  Before that I liked
cfdisk.  Anyway, how do I set up that partition with cgdisk?  Any
minimum size requirements or tiny is enough?  Does it have to be a
specific type?  Does it need to be in a specific place?  Formatted with
a file system?  Also, when I do grub-install, do I still point to
/dev/sda or to /dev/sda1, if sda1 is the special boot partition?

I tried to find a step by step howto with this info but the ones I find
either don't work or leaves me more confused.  Given that the method is
also aging out, it's hard to find good guides.  I'd be real happy just
to have a link to a good howto that I can make sense of.  I can save a
copy local and even print it.  Maybe someone has some notes that will
help.  I just need something to help clear up the muddy waters. 

Thanks to anyone who has a link, some notes or something.  :-D 

Dale

:-)  :-) 

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Wojciech Kuzyszyn]

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On Sat, 27 Apr 2024 11:53:25 -0500
Dale <rdalek1967@gmail.com> wrote:

> Howdy,
> 
> I'm installing Gentoo on another old box.  To be consistent I like to
> use cgdisk, GPT I think it is called, to partition all my drives,
> regardless of size.  Thing is, Grub works differently with GPT than it
> does with the old DOS or whatever it is called, like fdisk does in the
> old days.  I did some research but still find myself in some muddy
> waters.  My take on some things I've read, I need a boot partition,
> not to be confused with the /boot for kernels, init thingys and such.
>  Where I get lost, most use gdisk.  I like cgdisk.  Before that I
> liked cfdisk.  Anyway, how do I set up that partition with cgdisk?
> Any minimum size requirements or tiny is enough?  Does it have to be a
> specific type?  Does it need to be in a specific place?  Formatted
> with a file system?  Also, when I do grub-install, do I still point to
> /dev/sda or to /dev/sda1, if sda1 is the special boot partition?
> 
> I tried to find a step by step howto with this info but the ones I
> find either don't work or leaves me more confused.  Given that the
> method is also aging out, it's hard to find good guides.  I'd be real
> happy just to have a link to a good howto that I can make sense of.
> I can save a copy local and even print it.  Maybe someone has some
> notes that will help.  I just need something to help clear up the
> muddy waters. 
> 
> Thanks to anyone who has a link, some notes or something.  :-D 
> 
> Dale
> 
> :-)  :-) 
> 

I don't use cgdisk nor gdisk. Here's a link to Arch's wiki about GPT on
BIOS systems:

https://wiki.archlinux.org/title/GRUB#GUID_Partition_Table_(GPT)_specific_instructions

I guess you need to set the same code as in gdisk, or something similar
to BIOS boot or bios_grub as are in other such tools.

Good luck!

Wojciech

-- 
xWK

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Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Mark Knecht]

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On Sat, Apr 27, 2024 at 9:53 AM Dale <rdalek1967@gmail.com> wrote:
>
> Howdy,
>
> I'm installing Gentoo on another old box.  To be consistent I like to
> use cgdisk, GPT I think it is called, to partition all my drives,
> regardless of size.  Thing is, Grub works differently with GPT than it
> does with the old DOS or whatever it is called, like fdisk does in the
> old days.  I did some research but still find myself in some muddy
> waters.  My take on some things I've read, I need a boot partition, not
> to be confused with the /boot for kernels, init thingys and such.  Where
> I get lost, most use gdisk.  I like cgdisk.  Before that I liked
> cfdisk.  Anyway, how do I set up that partition with cgdisk?  Any
> minimum size requirements or tiny is enough?  Does it have to be a
> specific type?  Does it need to be in a specific place?  Formatted with
> a file system?  Also, when I do grub-install, do I still point to
> /dev/sda or to /dev/sda1, if sda1 is the special boot partition?
>
> I tried to find a step by step howto with this info but the ones I find
> either don't work or leaves me more confused.  Given that the method is
> also aging out, it's hard to find good guides.  I'd be real happy just
> to have a link to a good howto that I can make sense of.  I can save a
> copy local and even print it.  Maybe someone has some notes that will
> help.  I just need something to help clear up the muddy waters.
>
> Thanks to anyone who has a link, some notes or something.  :-D
>
> Dale
>
> :-)  :-)

I think I'm not really understanding your request because I only
remember fdisk from the old days, and none of your cfdisk and
cgdisk apps.

If you're working with disk in your new old-box machine then
I'd suggest trying gparted as it pretty much does everything
I've ever needed. It's minimally graphical, can changes the
partition type and boot flags.

This is just one of a billion pages you might look at:

https://linuxiac.com/how-to-use-gparted-to-create-and-resize-partitions/

Wishing you the best of luck,
Mark

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Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

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On Saturday, 27 April 2024 17:53:25 BST Dale wrote:
> Howdy,
> 
> I'm installing Gentoo on another old box.  To be consistent I like to
> use cgdisk, GPT I think it is called, to partition all my drives,
> regardless of size.

GPT is the partition table structure, which is more advanced than the old DOS 
partition table structure.


> Thing is, Grub works differently with GPT than it
> does with the old DOS or whatever it is called, like fdisk does in the
> old days.

GRUB works the same, but the disk/partition table structure is different.


> I did some research but still find myself in some muddy
> waters.  My take on some things I've read, I need a boot partition, not
> to be confused with the /boot for kernels, init thingys and such.  Where
> I get lost, most use gdisk.  I like cgdisk.  Before that I liked
> cfdisk.  Anyway, how do I set up that partition with cgdisk?  Any
> minimum size requirements or tiny is enough?

1MB

> Does it have to be a
> specific type?

Yes, it has to be set up as a "BIOS Boot Partition", with the "ef02", or GUID 
21686148-6449-6E6F-744E-656564454649.


> Does it need to be in a specific place?  

Not necessarily, but since you're not booting this disk on a UEFI MoBo and 
consequently won't be using an EFI System Partition (ESP), the very first 
partition is fine and will be out of the way of the remaining disk.


> Formatted with a file system?

Do not format it.  The raw 1MB partition will be used by GRUB to install its 
core.img file.


> Also, when I do grub-install, do I still point to
> /dev/sda or to /dev/sda1, if sda1 is the special boot partition?

Sector 0 of your disk /dev/sda is where GRUB will drop its boot loader image 
'boot.img'.  This is the Master Boot Record region.

Normally, with a DOS partition table, GRUB's core.img would be dropped in the 
empty space of sector 1, following sector 0.  However, in the GPT structure 
sector 1 is where the GPT partition array data is stored.  You don't want GRUB 
making a mess by dropping it's core.img on top of it!

So, from what I recall you'd install GRUB like so:

grub-install --boot-directory=/mnt/gentoo/boot --force /dev/sda

If this won't do it, I'll have to boot an old system of mine to check the disk 
layout in more detail.


> I tried to find a step by step howto with this info but the ones I find
> either don't work or leaves me more confused.  Given that the method is
> also aging out, it's hard to find good guides.  I'd be real happy just
> to have a link to a good howto that I can make sense of.  I can save a
> copy local and even print it.  Maybe someone has some notes that will
> help.  I just need something to help clear up the muddy waters. 
> 
> Thanks to anyone who has a link, some notes or something.  :-D 
> 
> Dale
> 
> :-)  :-) 


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Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Michael wrote:
> On Saturday, 27 April 2024 17:53:25 BST Dale wrote:
>> Howdy,
>>
>> I'm installing Gentoo on another old box.  To be consistent I like to
>> use cgdisk, GPT I think it is called, to partition all my drives,
>> regardless of size.
> GPT is the partition table structure, which is more advanced than the old DOS 
> partition table structure.
>

I just wasn't 100% sure what it was called. 

>> Thing is, Grub works differently with GPT than it
>> does with the old DOS or whatever it is called, like fdisk does in the
>> old days.
> GRUB works the same, but the disk/partition table structure is different.
>
>
>> I did some research but still find myself in some muddy
>> waters.  My take on some things I've read, I need a boot partition, not
>> to be confused with the /boot for kernels, init thingys and such.  Where
>> I get lost, most use gdisk.  I like cgdisk.  Before that I liked
>> cfdisk.  Anyway, how do I set up that partition with cgdisk?  Any
>> minimum size requirements or tiny is enough?
> 1MB

OK.  You know that "alignment" thing that is always on the beginning of
a drive, could it use it?  I think it is like 2MBs or something. 

>> Does it have to be a
>> specific type?
> Yes, it has to be set up as a "BIOS Boot Partition", with the "ef02", or GUID 
> 21686148-6449-6E6F-744E-656564454649.
>

Light bulb moment.  I've seen 8300 and friends, 8200 etc but never seen
EF02 before.  Now I see what that type means.  That cleared up some
muddy water.  That lead me to finding this, it has a nice table of
common codes. 

https://wiki.archlinux.org/title/GPT_fdisk



>> Does it need to be in a specific place?  
> Not necessarily, but since you're not booting this disk on a UEFI MoBo and 
> consequently won't be using an EFI System Partition (ESP), the very first 
> partition is fine and will be out of the way of the remaining disk.
>
>
>> Formatted with a file system?
> Do not format it.  The raw 1MB partition will be used by GRUB to install its 
> core.img file.
>
>
>> Also, when I do grub-install, do I still point to
>> /dev/sda or to /dev/sda1, if sda1 is the special boot partition?
> Sector 0 of your disk /dev/sda is where GRUB will drop its boot loader image 
> 'boot.img'.  This is the Master Boot Record region.
>
> Normally, with a DOS partition table, GRUB's core.img would be dropped in the 
> empty space of sector 1, following sector 0.  However, in the GPT structure 
> sector 1 is where the GPT partition array data is stored.  You don't want GRUB 
> making a mess by dropping it's core.img on top of it!
>
> So, from what I recall you'd install GRUB like so:
>
> grub-install --boot-directory=/mnt/gentoo/boot --force /dev/sda
>
> If this won't do it, I'll have to boot an old system of mine to check the disk 
> layout in more detail.
>
>

I may look on youtube and see if I can find someone setting up a disk. 
It may have a video, old one for sure.  Maybe that will help me make
sense of it even more.  I think I got figured out how to use cgdisk now
but installing grub may require some more details. 

What I find odd, most of the howtos I found don't show example outputs. 
Then again, it could just work.  O_o

Thanks to all. 

Dale

:-)  :-)

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

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On Sunday, 28 April 2024 06:24:09 BST Dale wrote:
> Michael wrote:
> > On Saturday, 27 April 2024 17:53:25 BST Dale wrote:
[snip ...]

> >> I did some research but still find myself in some muddy
> >> waters.  My take on some things I've read, I need a boot partition, not
> >> to be confused with the /boot for kernels, init thingys and such.  Where
> >> I get lost, most use gdisk.  I like cgdisk.  Before that I liked
> >> cfdisk.  Anyway, how do I set up that partition with cgdisk?  Any
> >> minimum size requirements or tiny is enough?
> > 
> > 1MB
> 
> OK.  You know that "alignment" thing that is always on the beginning of
> a drive, could it use it?  I think it is like 2MBs or something. 

It should be 1MB, sector 2048.  For 512 byte sector size you'd get:

2048 x 512 = 1,048,576 bytes

This is coded in on modern partitioning tools to ensure alignment of logical 
and physical sectors by default.  This alignment is critical for the 
performance of so called "Advanced Format" disks with 4096 byte size of 
physical sectors.  Therefore I strongly suggest you let the partitioning tool 
align its logical partitions where it feels best - at the 1MB boundary and not 
change it.

HOWEVER ...

If you are partitioning an old disk on a BIOS MoBo with logical/physical 
sector sizes both at 512/512 bytes, then you can take matters into your own 
hands and force it to start your 'BIOS Boot Partition' at sector 34.  Sectors 
0-33 are used by the MBR and the GPT headers, so leave these alone.

Start sector 34
End sector 2047


> >> Does it have to be a
> >> specific type?
> > 
> > Yes, it has to be set up as a "BIOS Boot Partition", with the "ef02", or
> > GUID 21686148-6449-6E6F-744E-656564454649.
> 
> Light bulb moment.  I've seen 8300 and friends, 8200 etc but never seen
> EF02 before.  Now I see what that type means.  That cleared up some
> muddy water.  That lead me to finding this, it has a nice table of
> common codes. 
> 
> https://wiki.archlinux.org/title/GPT_fdisk

If you select [Type] in cgdisk and then press "L" it will list all the 
partition types available.

I suggest you familiarise yourself with gdisk, which has more options, or as 
already suggested GParted has an easy GUI to navigate through.

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[gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Grant Edwards]

On 2024-04-27, Michael <confabulate@kintzios.com> wrote:
> On Saturday, 27 April 2024 17:53:25 BST Dale wrote:
>> Howdy,
>> 
>> I'm installing Gentoo on another old box.  To be consistent I like
>> to use cgdisk, GPT I think it is called, to partition all my
>> drives, regardless of size.
>
> GPT is the partition table structure, which is more advanced than
> the old DOS partition table structure.
>
>> Thing is, Grub works differently with GPT than it does with the old
>> DOS or whatever it is called, like fdisk does in the old days.
>
> GRUB works the same, but the disk/partition table structure is different.

No, grub doesn't work the with GPT disk labels as it did with DOS disk
labels.

With DOS disk lables, Grub uses empty space between the boot sector
and the first partition as a location to store it's core image file.
That empty space does not exist when using GPT disk label. When using
a GPT disk label, Grub requires that you need to create a "BIOS Boot"
or "Grub Boot" partition so that Grub has somwhere to store it's core
image[1].

https://wiki.gentoo.org/wiki/GRUB#BIOS_with_GPT
https://wiki.archlinux.org/title/GRUB#BIOS_systems


[1] There is an alternative installation method where Grub will record
    the disk block numbers occupied by the core image files as they
    reside in the normal filesystem.  That's extra work to maintain
    and might not be reliable for some filesystem types, so it's not
    recommended.

[gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Grant Edwards]

On 2024-04-28, Grant Edwards <grant.b.edwards@gmail.com> wrote:

> With DOS disk lables, Grub uses empty space between the boot sector
> and the first partition as a location to store it's core image file.
> That empty space does not exist when using GPT disk label. When using
> a GPT disk label, Grub requires that you need to create a "BIOS Boot"
> or "Grub Boot" partition so that Grub has somwhere to store it's core
> image[1].

And it bears repeating that the bios/grub boot partition only needs to
be 1 or 2MB in size, is _not_ formatted with a filesystem, and is
_not_ the same as either

 1) The "boot" directory where the kernel images and grubs other files
    are installed within a Linux filesystem. [Which you still need
    when booting in Legacy/BIOS mode.]

  or

 2) The UEFI partition that's formated with a FAT filesystem and used
    in UEFI boot mode [which you don't need when booting in
    Legacy/BIOS mode.]

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Grant Edwards wrote:
> On 2024-04-28, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>
>> With DOS disk lables, Grub uses empty space between the boot sector
>> and the first partition as a location to store it's core image file.
>> That empty space does not exist when using GPT disk label. When using
>> a GPT disk label, Grub requires that you need to create a "BIOS Boot"
>> or "Grub Boot" partition so that Grub has somwhere to store it's core
>> image[1].
> And it bears repeating that the bios/grub boot partition only needs to
> be 1 or 2MB in size, is _not_ formatted with a filesystem, and is
> _not_ the same as either
>
>  1) The "boot" directory where the kernel images and grubs other files
>     are installed within a Linux filesystem. [Which you still need
>     when booting in Legacy/BIOS mode.]
>
>   or
>
>  2) The UEFI partition that's formated with a FAT filesystem and used
>     in UEFI boot mode [which you don't need when booting in
>     Legacy/BIOS mode.]
>


I think I got a grasp on this now.  Basically, partitions should be like
this. 


First spot is the alignment thing.  Usually a few MBs or so and unused.

Grub boot partition with ef02 setting, not to be formatted.

/boot partition for kernel and init thingy.  Usually 1GB or so, enough
for memtest, bootable rescue image etc. 

/ or root partition that is around 150GBs or so.  Enough to expand a bit
and includes /usr and /var.

/home  rest of disk unless some needed for something else.


Do you recall when running grub-install what that command looks like? 
Lets say the Grub partition with ef02 setting is sda1, would it be
grub-install /dev/sda1 or just sda and it finds the empty partition on
its own?  That's the only thing I'm not real sure of at this point.  I
think it is sda.  Maybe. ;-)

Or is all that above just plain wrong?  O-o 

Dale

:-)  :-) 

P. S.  Been on tractor with a box blade.  Did three very long driveways
and a couple short ones.  My neighbors have smooth driveways again.  :-D 

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

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On Sunday, 28 April 2024 19:39:16 BST Dale wrote:
> Grant Edwards wrote:
> > On 2024-04-28, Grant Edwards <grant.b.edwards@gmail.com> wrote:
> >> With DOS disk lables, Grub uses empty space between the boot sector
> >> and the first partition as a location to store it's core image file.
> >> That empty space does not exist when using GPT disk label. When using
> >> a GPT disk label, Grub requires that you need to create a "BIOS Boot"
> >> or "Grub Boot" partition so that Grub has somwhere to store it's core
> >> image[1].
> > 
> > And it bears repeating that the bios/grub boot partition only needs to
> > be 1 or 2MB in size, is _not_ formatted with a filesystem, and is
> > _not_ the same as either
> > 
> >  1) The "boot" directory where the kernel images and grubs other files
> >  
> >     are installed within a Linux filesystem. [Which you still need
> >     when booting in Legacy/BIOS mode.]
> >   
> >   or
> >  
> >  2) The UEFI partition that's formated with a FAT filesystem and used
> >  
> >     in UEFI boot mode [which you don't need when booting in
> >     Legacy/BIOS mode.]
> 
> I think I got a grasp on this now.  Basically, partitions should be like
> this. 
> 
> 
> First spot is the alignment thing.  Usually a few MBs or so and unused.

This is created automatically by the partitioning tool, in your case cgdisk, 
when you create the first partition on the disk and accept the default 
starting sector.


> Grub boot partition with ef02 setting, not to be formatted.
> 
> /boot partition for kernel and init thingy.  Usually 1GB or so, enough
> for memtest, bootable rescue image etc. 
> 
> / or root partition that is around 150GBs or so.  Enough to expand a bit
> and includes /usr and /var.
> 
> /home  rest of disk unless some needed for something else.
> 
> 
> Do you recall when running grub-install what that command looks like? 
> Lets say the Grub partition with ef02 setting is sda1, would it be
> grub-install /dev/sda1 or just sda and it finds the empty partition on
> its own?

The unformatted and empty /dev/sda1 'BIOS Boot Partition' will be found by 
GRUB when you run grub-install and it will store its core.img in there.

You install GRUB's boot.img in the MBR and therefore you have to specify the 
disk, NOT a partition, e.g.:

grub-install /dev/sda

This command should:

1. Install GRUB's boot.img in the MBR of /dev/sda.
2. Install GRUB's core.img in /dev/sda1 which you created as a 'BIOS boot 
partition', type EF02.
3. Create directory /boot/grub to install all the grub fs drivers and files.

If you have mounted /boot, all is well.  If you are repairing an installation 
from a liveUSB you can mount the /boot partition, e.g. /mnt/gentoo/boot and 
specify this in the CLI:

grub-install --boot-directory=/mnt/gentoo/boot /dev/sda

NOTE:  As per the link Grant helpfully posted you can create the 'BIOS boot 
partition' with cgdisk "... by setting the partition type to 0xEF02 and giving 
it a label of gptbios".

https://wiki.gentoo.org/wiki/GRUB#BIOS_with_GPT


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Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Michael wrote:
> On Sunday, 28 April 2024 19:39:16 BST Dale wrote:
>> Grant Edwards wrote:
>>> On 2024-04-28, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>>>> With DOS disk lables, Grub uses empty space between the boot sector
>>>> and the first partition as a location to store it's core image file.
>>>> That empty space does not exist when using GPT disk label. When using
>>>> a GPT disk label, Grub requires that you need to create a "BIOS Boot"
>>>> or "Grub Boot" partition so that Grub has somwhere to store it's core
>>>> image[1].
>>> And it bears repeating that the bios/grub boot partition only needs to
>>> be 1 or 2MB in size, is _not_ formatted with a filesystem, and is
>>> _not_ the same as either
>>>
>>>  1) The "boot" directory where the kernel images and grubs other files
>>>  
>>>     are installed within a Linux filesystem. [Which you still need
>>>     when booting in Legacy/BIOS mode.]
>>>   
>>>   or
>>>  
>>>  2) The UEFI partition that's formated with a FAT filesystem and used
>>>  
>>>     in UEFI boot mode [which you don't need when booting in
>>>     Legacy/BIOS mode.]
>> I think I got a grasp on this now.  Basically, partitions should be like
>> this. 
>>
>>
>> First spot is the alignment thing.  Usually a few MBs or so and unused.
> This is created automatically by the partitioning tool, in your case cgdisk, 
> when you create the first partition on the disk and accept the default 
> starting sector.
>
>
>> Grub boot partition with ef02 setting, not to be formatted.
>>
>> /boot partition for kernel and init thingy.  Usually 1GB or so, enough
>> for memtest, bootable rescue image etc. 
>>
>> / or root partition that is around 150GBs or so.  Enough to expand a bit
>> and includes /usr and /var.
>>
>> /home  rest of disk unless some needed for something else.
>>
>>
>> Do you recall when running grub-install what that command looks like? 
>> Lets say the Grub partition with ef02 setting is sda1, would it be
>> grub-install /dev/sda1 or just sda and it finds the empty partition on
>> its own?
> The unformatted and empty /dev/sda1 'BIOS Boot Partition' will be found by 
> GRUB when you run grub-install and it will store its core.img in there.
>
> You install GRUB's boot.img in the MBR and therefore you have to specify the 
> disk, NOT a partition, e.g.:
>
> grub-install /dev/sda
>
> This command should:
>
> 1. Install GRUB's boot.img in the MBR of /dev/sda.
> 2. Install GRUB's core.img in /dev/sda1 which you created as a 'BIOS boot 
> partition', type EF02.
> 3. Create directory /boot/grub to install all the grub fs drivers and files.
>
> If you have mounted /boot, all is well.  If you are repairing an installation 
> from a liveUSB you can mount the /boot partition, e.g. /mnt/gentoo/boot and 
> specify this in the CLI:
>
> grub-install --boot-directory=/mnt/gentoo/boot /dev/sda
>
> NOTE:  As per the link Grant helpfully posted you can create the 'BIOS boot 
> partition' with cgdisk "... by setting the partition type to 0xEF02 and giving 
> it a label of gptbios".
>
> https://wiki.gentoo.org/wiki/GRUB#BIOS_with_GPT
>

That's what I was thinking.  I think I got it.  I need to make notes of
this tho.  Before I forget.  :/ 

Thanks to all.

Dale

:-)  :-) 

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Dale wrote:
> Michael wrote:
>> On Sunday, 28 April 2024 19:39:16 BST Dale wrote:
>>> Grant Edwards wrote:
>>>> On 2024-04-28, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>>>>> With DOS disk lables, Grub uses empty space between the boot sector
>>>>> and the first partition as a location to store it's core image file.
>>>>> That empty space does not exist when using GPT disk label. When using
>>>>> a GPT disk label, Grub requires that you need to create a "BIOS Boot"
>>>>> or "Grub Boot" partition so that Grub has somwhere to store it's core
>>>>> image[1].
>>>> And it bears repeating that the bios/grub boot partition only needs to
>>>> be 1 or 2MB in size, is _not_ formatted with a filesystem, and is
>>>> _not_ the same as either
>>>>
>>>>  1) The "boot" directory where the kernel images and grubs other files
>>>>  
>>>>     are installed within a Linux filesystem. [Which you still need
>>>>     when booting in Legacy/BIOS mode.]
>>>>   
>>>>   or
>>>>  
>>>>  2) The UEFI partition that's formated with a FAT filesystem and used
>>>>  
>>>>     in UEFI boot mode [which you don't need when booting in
>>>>     Legacy/BIOS mode.]
>>> I think I got a grasp on this now.  Basically, partitions should be like
>>> this. 
>>>
>>>
>>> First spot is the alignment thing.  Usually a few MBs or so and unused.
>> This is created automatically by the partitioning tool, in your case cgdisk, 
>> when you create the first partition on the disk and accept the default 
>> starting sector.
>>
>>
>>> Grub boot partition with ef02 setting, not to be formatted.
>>>
>>> /boot partition for kernel and init thingy.  Usually 1GB or so, enough
>>> for memtest, bootable rescue image etc. 
>>>
>>> / or root partition that is around 150GBs or so.  Enough to expand a bit
>>> and includes /usr and /var.
>>>
>>> /home  rest of disk unless some needed for something else.
>>>
>>>
>>> Do you recall when running grub-install what that command looks like? 
>>> Lets say the Grub partition with ef02 setting is sda1, would it be
>>> grub-install /dev/sda1 or just sda and it finds the empty partition on
>>> its own?
>> The unformatted and empty /dev/sda1 'BIOS Boot Partition' will be found by 
>> GRUB when you run grub-install and it will store its core.img in there.
>>
>> You install GRUB's boot.img in the MBR and therefore you have to specify the 
>> disk, NOT a partition, e.g.:
>>
>> grub-install /dev/sda
>>
>> This command should:
>>
>> 1. Install GRUB's boot.img in the MBR of /dev/sda.
>> 2. Install GRUB's core.img in /dev/sda1 which you created as a 'BIOS boot 
>> partition', type EF02.
>> 3. Create directory /boot/grub to install all the grub fs drivers and files.
>>
>> If you have mounted /boot, all is well.  If you are repairing an installation 
>> from a liveUSB you can mount the /boot partition, e.g. /mnt/gentoo/boot and 
>> specify this in the CLI:
>>
>> grub-install --boot-directory=/mnt/gentoo/boot /dev/sda
>>
>> NOTE:  As per the link Grant helpfully posted you can create the 'BIOS boot 
>> partition' with cgdisk "... by setting the partition type to 0xEF02 and giving 
>> it a label of gptbios".
>>
>> https://wiki.gentoo.org/wiki/GRUB#BIOS_with_GPT
>>
> That's what I was thinking.  I think I got it.  I need to make notes of
> this tho.  Before I forget.  :/ 
>
> Thanks to all.
>
> Dale
>
> :-)  :-) 
>


One last update.  I found a video.  They were using gdisk but the
crucial part, he got it to display the partition layout.  It was like I
described as for as the alignment thing, tiny partition with ef02 and
then carry on as usual from there. 

I need to do this on a disk complete with notes, so I don't forget.  My
brain is going fast.  One day, I'll forget how to turn the puter on. 
:'(  I already forget what I went to the kitchen for, it's only 20 feet
away.  :/

Thanks again. 

Dale

:-)  :-)

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Dale wrote:
> One last update.  I found a video.  They were using gdisk but the
> crucial part, he got it to display the partition layout.  It was like I
> described as for as the alignment thing, tiny partition with ef02 and
> then carry on as usual from there. 
>
> I need to do this on a disk complete with notes, so I don't forget.  My
> brain is going fast.  One day, I'll forget how to turn the puter on. 
> :'(  I already forget what I went to the kitchen for, it's only 20 feet
> away.  :/
>
> Thanks again. 
>
> Dale
>
> :-)  :-)
>


OK.  One last update in case someone googles and runs up on this
thread.  I'm using gdisk to display this, because I think it will do
better in email.  If I use cgdisk, it is wider and will wrap more.  This
is what the partition table looks like for GPT, old BIOS and no uefi
thingy.  Just a straight forward and simple old school setup.  Once the
first one is done, the rest can be anything.


Number  Start (sector)    End (sector)  Size       Code     Name
   1            2048             10239          4.0 MiB     EF02  BIOS-boot
   2           10240            4204543      2.0 GiB     8300  boot
   3         4204544          12593151    4.0 GiB     8300  swap
   4        12593152        327165951   150.0 GiB   8300  root
   5       327165952       625141759   142.1 GiB   8300  home


I'm about to start a fresh install on this so if it isn't right, let me
know soon.  I did make it a little larger than everyone says it needs to
be since grub does seem to grow.  That should be bigger than I'll ever
need in the lifetime of this old rig anyway. 

Dale

:-)  :-) 

[gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Grant Edwards]

On 2024-05-01, Dale <rdalek1967@gmail.com> wrote:

> OK.  One last update in case someone googles and runs up on this
> thread.  I'm using gdisk to display this, because I think it will do
> better in email.  If I use cgdisk, it is wider and will wrap more. 
> This is what the partition table looks like for GPT, old BIOS and no
> uefi thingy.  Just a straight forward and simple old school setup. 
> Once the first one is done, the rest can be anything.
>
>
> Number  Start (sector)    End (sector)  Size       Code     Name
>    1            2048             10239          4.0 MiB     EF02  BIOS-boot
>    2           10240            4204543      2.0 GiB     8300  boot
>    3         4204544          12593151    4.0 GiB     8300  swap
>    4        12593152        327165951   150.0 GiB   8300  root
>    5       327165952       625141759   142.1 GiB   8300  home

The partition type code for 'swap' is wrong -- it should be
8200. According to the gdisk help info Linux /home is supposed to be
8302, but I've always used the same generic "Linux filesystem" type
for both /home and root.

Is the 'boot' partition for future possible UEFI use, for Linux /boot,
or both?  [I've never used a separate partition for Linux /boot, I
just use a /boot directory on the root FS.]

--
Grant

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Grant Edwards wrote:
> On 2024-05-01, Dale <rdalek1967@gmail.com> wrote:
>
>> OK.  One last update in case someone googles and runs up on this
>> thread.  I'm using gdisk to display this, because I think it will do
>> better in email.  If I use cgdisk, it is wider and will wrap more. 
>> This is what the partition table looks like for GPT, old BIOS and no
>> uefi thingy.  Just a straight forward and simple old school setup. 
>> Once the first one is done, the rest can be anything.
>>
>>
>> Number  Start (sector)    End (sector)  Size       Code     Name
>>    1            2048             10239          4.0 MiB     EF02  BIOS-boot
>>    2           10240            4204543      2.0 GiB     8300  boot
>>    3         4204544          12593151    4.0 GiB     8300  swap
>>    4        12593152        327165951   150.0 GiB   8300  root
>>    5       327165952       625141759   142.1 GiB   8300  home
> The partition type code for 'swap' is wrong -- it should be
> 8200. According to the gdisk help info Linux /home is supposed to be
> 8302, but I've always used the same generic "Linux filesystem" type
> for both /home and root.
>
> Is the 'boot' partition for future possible UEFI use, for Linux /boot,
> or both?  [I've never used a separate partition for Linux /boot, I
> just use a /boot directory on the root FS.]
>
> --
> Grant

I noticed the other day that some new ones was added.  I always leave it
as 8300 and it works.  It even works for swap.  I dunno. 

The /boot is where kernels and init thingys go.  Keep in mind, this is
on a old rig that has no idea what UEFI is.  When I build my new rig
later, I'll do a install from scratch anyway.  Also, it will go on a SSD. 

I mostly want to post so that a person can see the layout.  Really, the
first one is what a person wanting to use GPT on a old BIOS system needs
to see.  After that, they can do partitions anyway they want.  I just
hope I got it right.  Right now, I'm to the stage where I do a emerge
-auDN world.  On that old rig, may take a little bit.  It's not bad
tho.  Old rig has 6 cores now. 

Dale

:-)  :-) 

[gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Grant Edwards]

On 2024-05-01, Dale <rdalek1967@gmail.com> wrote:
> Grant Edwards wrote:
>
>> The partition type code for 'swap' is wrong -- it should be
>> 8200. According to the gdisk help info Linux /home is supposed to be
>> 8302, but I've always used the same generic "Linux filesystem" type
>> for both /home and root.
>>
>> Is the 'boot' partition for future possible UEFI use, for Linux /boot,
>> or both?  [I've never used a separate partition for Linux /boot, I
>> just use a /boot directory on the root FS.]
>
> I noticed the other day that some new ones was added.  I always leave it
> as 8300 and it works.  It even works for swap.  I dunno. 

If you have an entry in /etc/fstab for swap, it might not matter if
the partition type is set to 'Linux swap' or not. I always set the
swap parition type to 'Linux swap', and then it doesn't seem to matter
if there's a swap entry in the fstab or not.

> The /boot is where kernels and init thingys go.  Keep in mind, this is
> on a old rig that has no idea what UEFI is.  When I build my new rig
> later, I'll do a install from scratch anyway.  Also, it will go on a SSD. 

OK, so 'boot' is for the Linux /boot directory.  I was just curious
since I had never used one. 

> I mostly want to post so that a person can see the layout.  Really, the
> first one is what a person wanting to use GPT on a old BIOS system needs
> to see.  After that, they can do partitions anyway they want.

Right.

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Grant Edwards wrote:
> On 2024-05-01, Dale <rdalek1967@gmail.com> wrote:
>> Grant Edwards wrote:
>>
>>> The partition type code for 'swap' is wrong -- it should be
>>> 8200. According to the gdisk help info Linux /home is supposed to be
>>> 8302, but I've always used the same generic "Linux filesystem" type
>>> for both /home and root.
>>>
>>> Is the 'boot' partition for future possible UEFI use, for Linux /boot,
>>> or both?  [I've never used a separate partition for Linux /boot, I
>>> just use a /boot directory on the root FS.]
>> I noticed the other day that some new ones was added.  I always leave it
>> as 8300 and it works.  It even works for swap.  I dunno. 
> If you have an entry in /etc/fstab for swap, it might not matter if
> the partition type is set to 'Linux swap' or not. I always set the
> swap parition type to 'Linux swap', and then it doesn't seem to matter
> if there's a swap entry in the fstab or not.

I tend to put everything in fstab.  It's the way it was when I started
and I just keep doing it that way.  It could be that it isn't needed
anymore tho. 


>> The /boot is where kernels and init thingys go.  Keep in mind, this is
>> on a old rig that has no idea what UEFI is.  When I build my new rig
>> later, I'll do a install from scratch anyway.  Also, it will go on a SSD. 
> OK, so 'boot' is for the Linux /boot directory.  I was just curious
> since I had never used one. 
>

I've used one ever since I started using Linux and it's as much habit as
anything.  Given the size of drives nowadays, I have started putting
/usr and /var on the root partition.  When I build my new rig tho, odds
are /var will be on its own partition.  That way if a log file goes
wonky, it can fill it up and not really do any harm. 


>> I mostly want to post so that a person can see the layout.  Really, the
>> first one is what a person wanting to use GPT on a old BIOS system needs
>> to see.  After that, they can do partitions anyway they want.
> Right.


I'm to the good part of the install now.  With the partition layout
shown earlier, I get this. 


(chroot) livecd / # grub-install /dev/sda
Installing for i386-pc platform.
Installation finished. No error reported.
(chroot) livecd / #


When I did that before, it puked on my keyboard.  This time with that
little unformatted partition, it just installed it.  So, muddy waters
pretty clear now.  :-D 

Dale

:-)  :-) 

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

[-- Attachment #1: Type: text/plain, Size: 1553 bytes --]

On Thursday, 2 May 2024 00:45:29 BST Dale wrote:
> Grant Edwards wrote:
> > On 2024-05-01, Dale <rdalek1967@gmail.com> wrote:
> >> Grant Edwards wrote:
> >>> The partition type code for 'swap' is wrong -- it should be
> >>> 8200. According to the gdisk help info Linux /home is supposed to be
> >>> 8302, but I've always used the same generic "Linux filesystem" type
> >>> for both /home and root.
> >>> 
> >>> Is the 'boot' partition for future possible UEFI use, for Linux /boot,
> >>> or both?  [I've never used a separate partition for Linux /boot, I
> >>> just use a /boot directory on the root FS.]
> >> 
> >> I noticed the other day that some new ones was added.  I always leave it
> >> as 8300 and it works.  It even works for swap.  I dunno. 

In the legacy DOS partition tables the space available was limited to 32 bits, 
while the GPT table specification provides 128 bytes for each block entry.  
The extra space can be used to store information related to the intended OS 
usage of each partition, by adding the corresponding Partition Type UUID.

This has a number of benefits, described here:

https://uapi-group.org/specifications/specs/
discoverable_partitions_specification/

Besides the automation this feature affords, I find it useful to know what a 
partition contains without having to mount it.  On GPT labelled disks I make 
use both of the Partition Type UUID and the Partition Name.  A quick glance at 
the gdisk output and if need be its 'i' option has saved my day from 
formatting the wrong partition more than once!  ;-)

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Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Michael wrote:
> On Thursday, 2 May 2024 00:45:29 BST Dale wrote:
>> Grant Edwards wrote:
>>> On 2024-05-01, Dale <rdalek1967@gmail.com> wrote:
>>>> Grant Edwards wrote:
>>>>> The partition type code for 'swap' is wrong -- it should be
>>>>> 8200. According to the gdisk help info Linux /home is supposed to be
>>>>> 8302, but I've always used the same generic "Linux filesystem" type
>>>>> for both /home and root.
>>>>>
>>>>> Is the 'boot' partition for future possible UEFI use, for Linux /boot,
>>>>> or both?  [I've never used a separate partition for Linux /boot, I
>>>>> just use a /boot directory on the root FS.]
>>>> I noticed the other day that some new ones was added.  I always leave it
>>>> as 8300 and it works.  It even works for swap.  I dunno. 
> In the legacy DOS partition tables the space available was limited to 32 bits, 
> while the GPT table specification provides 128 bytes for each block entry.  
> The extra space can be used to store information related to the intended OS 
> usage of each partition, by adding the corresponding Partition Type UUID.
>
> This has a number of benefits, described here:
>
> https://uapi-group.org/specifications/specs/
> discoverable_partitions_specification/
>
> Besides the automation this feature affords, I find it useful to know what a 
> partition contains without having to mount it.  On GPT labelled disks I make 
> use both of the Partition Type UUID and the Partition Name.  A quick glance at 
> the gdisk output and if need be its 'i' option has saved my day from 
> formatting the wrong partition more than once!  ;-)


I always use labels which show up with cgdisk.  If I'm unsure how I
partitioned a drive for some reason, I just check it with cgdisk to see
what is what.  I use labels even tho a lot of the time I put UUIDs in
fstab.  I do similar when using LVM as well. 

There is more than one way to organize things tho.  ;-) 

Dale

:-)  :-) 

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Wols Lists]

On 02/05/2024 10:35, Michael wrote:
> Besides the automation this feature affords, I find it useful to know what a
> partition contains without having to mount it.  On GPT labelled disks I make
> use both of the Partition Type UUID and the Partition Name.  A quick glance at
> the gdisk output and if need be its 'i' option has saved my day from
> formatting the wrong partition more than once!  😉

Iirc from the days of kernel 1.3 and 2.x, the partition type is not used 
- at all - by linux itself. Dunno about other OSs.

As you pointed out, though, it is used by other tools, which use it to 
identify what the partition is *supposed* to be used for. For example, 
auto-assemble with raid.

I'm not sure, but for example I think swap will quite happily let you 
"mount" a non-swap partiton with swap-on. You can format an allegedly 
DOS or NTFS partition with ext, and linux won't care ...

Cheers,
Wol

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Peter Humphrey]

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On Thursday, 2 May 2024 00:45:29 BST Dale wrote:
> Grant Edwards wrote:
> > OK, so 'boot' is for the Linux /boot directory.  I was just curious
> > since I had never used one.

When I started using Linux, the received wisdom was to keep a separate /boot, 
and leave it unmounted during normal operation. The idea was that a successful 
hacker would not, supposedly, be able to corrupt the kernel ready for a reboot 
into their system.

Old habits die hard, though, and besides, a separate /boot has been handy in 
the copious reinstallations I've been through.

> I've used one ever since I started using Linux and it's as much habit as
> anything.  Given the size of drives nowadays, I have started putting
> /usr and /var on the root partition.  When I build my new rig tho, odds
> are /var will be on its own partition.  That way if a log file goes
> wonky, it can fill it up and not really do any harm. 

I do that too. It also helps with backups and new installations.

-- 
Regards,
Peter.

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Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Wols Lists]

On 02/05/2024 11:46, Peter Humphrey wrote:
> When I started using Linux, the received wisdom was to keep a separate /boot,
> and leave it unmounted during normal operation. The idea was that a successful
> hacker would not, supposedly, be able to corrupt the kernel ready for a reboot
> into their system.

And you can't have /boot on your system partition if, like me, you have 
one instance of grub booting into several different OSs or distros ... 
Less so now, but having multiple distros on one system was a popular 
hobbyist pastime!

(One distro's system partition is another distro's data partion :-)

Cheers,
Wol

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Peter Humphrey]

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On Wednesday, 15 May 2024 08:42:14 BST Wols Lists wrote:
> On 02/05/2024 11:46, Peter Humphrey wrote:
> > When I started using Linux, the received wisdom was to keep a separate
> > /boot, and leave it unmounted during normal operation. The idea was that
> > a successful hacker would not, supposedly, be able to corrupt the kernel
> > ready for a reboot into their system.
> 
> And you can't have /boot on your system partition if, like me, you have
> one instance of grub booting into several different OSs or distros ...
> Less so now, but having multiple distros on one system was a popular
> hobbyist pastime!

I think whoever named grub had delusions of grandeur.  :)  Anyway, I never let 
it near my systems.

-- 
Regards,
Peter.

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Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Wols Lists]

On 15/05/2024 11:40, Peter Humphrey wrote:
> I think whoever named grub had delusions of grandeur.  🙂  Anyway, I never let
> it near my systems.

I liked lilo. And then it disappeared :-(

Grub isn't that bad - it's just that insists on trying to do everything 
itself - and if you've got at all a strange setup it makes a complete 
hash of it.

LIKE GENTOO!

I've moaned about this before, but last time SUSE updated itself, it 
trashed grub.conf and left me with an unbootable system. And then gentoo 
sees that I've got an unmounted /boot and throws a complete and utter 
hissy fit because I told it not to touch it ...

Cheers,
Wol

[gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Grant Edwards]

On 2024-05-15, Wols Lists <antlists@youngman.org.uk> wrote:
> On 15/05/2024 11:40, Peter Humphrey wrote:
>> I think whoever named grub had delusions of grandeur.  🙂  Anyway, I never let
>> it near my systems.
>
> I liked lilo. And then it disappeared :-(
>
> Grub isn't that bad - it's just that insists on trying to do everything 
> itself - and if you've got at all a strange setup it makes a complete 
> hash of it.

Grub2 is a bit overblown, but it's quite usable as long as you stick
to a manually generated grub.cfg file and stay away from the
auto-magical disk-probing configuration script world-domination
scheme.

--
Grant

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Peter Humphrey]

[-- Attachment #1: Type: text/plain, Size: 1018 bytes --]

On Wednesday, 15 May 2024 18:57:48 BST Grant Edwards wrote:
> On 2024-05-15, Wols Lists <antlists@youngman.org.uk> wrote:
> > On 15/05/2024 11:40, Peter Humphrey wrote:
> >> I think whoever named grub had delusions of grandeur.  🙂  Anyway, I
> >> never let it near my systems.
> > 
> > I liked lilo. And then it disappeared :-(
> > 
> > Grub isn't that bad - it's just that insists on trying to do everything
> > itself - and if you've got at all a strange setup it makes a complete
> > hash of it.
> 
> Grub2 is a bit overblown, but it's quite usable as long as you stick
> to a manually generated grub.cfg file and stay away from the
> auto-magical disk-probing configuration script world-domination
> scheme.

Which rather defeats its object, doesn't it?

Anyway, I use bootctl from the dreaded systemd. It enables me to choose a 
kernel at boot time, with no attempt to tell me what to do. All from small, 
simple files under /boot/loader/entries. Photo attached.

-- 
Regards,
Peter.

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Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[karl]

Wol:
> On 15/05/2024 11:40, Peter Humphrey wrote:
> > I think whoever named grub had delusions of grandeur.  🙂  Anyway, I never let
> > it near my systems.
> 
> I liked lilo. And then it disappeared :-(
...

 Still available and still working on non-uefi setups:
https://packages.gentoo.org/packages/sys-boot/lilo

Regards,
/Karl Hammar

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

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On Thursday, 16 May 2024 01:10:32 BST karl@aspodata.se wrote:
> Wol:
> > On 15/05/2024 11:40, Peter Humphrey wrote:
> > > I think whoever named grub had delusions of grandeur.  🙂  Anyway, I
> > > never let it near my systems.
> > 
> > I liked lilo. And then it disappeared :-(
> 
> ...
> 
>  Still available and still working on non-uefi setups:
> https://packages.gentoo.org/packages/sys-boot/lilo
> 
> Regards,
> /Karl Hammar

There's also 'sys-boot/elilo' for EFI systems.

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[gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Nuno Silva]

On 2024-05-16, Michael wrote:

> On Thursday, 16 May 2024 01:10:32 BST karl@aspodata.se wrote:
>> Wol:
>> > On 15/05/2024 11:40, Peter Humphrey wrote:
>> > > I think whoever named grub had delusions of grandeur.  🙂  Anyway, I
>> > > never let it near my systems.
>> > 
>> > I liked lilo. And then it disappeared :-(
>> 
>> ...
>> 
>>  Still available and still working on non-uefi setups:
>> https://packages.gentoo.org/packages/sys-boot/lilo
>> 
>> Regards,
>> /Karl Hammar
>
> There's also 'sys-boot/elilo' for EFI systems.

What about grub as in "grub1" or grub0.xx for PC BIOS, is it still
available (outside the main tree?) and working e.g. with patches, or is
there some unsolved compilation issue nowadays?

-- 
Nuno Silva

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dr Rainer Woitok]

Michael,

On Thursday, 2024-05-16 09:26:39 +0100, you wrote:

> ...
> > > I liked lilo. And then it disappeared :-(
> > ...
> >  Still available and still working on non-uefi setups:
> > https://packages.gentoo.org/packages/sys-boot/lilo
> > 
> > ...
> 
> There's also 'sys-boot/elilo' for EFI systems.

The homepage returned by

   $ eix --verbose sys-boot/elilo
   * sys-boot/elilo
        Available versions:  ~3.16-r5
        Homepage:            https://sourceforge.net/projects/elilo/
        Description:         Linux boot loader for EFI-based systems such as IA-64
        License:             GPL-2
   $

hints that this package is no longer maintained ... :-(

Sincerely,
  Rainer

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

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On Thursday, 16 May 2024 17:41:20 BST Dr Rainer Woitok wrote:
> Michael,
> 
> On Thursday, 2024-05-16 09:26:39 +0100, you wrote:
> > ...
> > 
> > > > I liked lilo. And then it disappeared :-(
> > > 
> > > ...
> > > 
> > >  Still available and still working on non-uefi setups:
> > > https://packages.gentoo.org/packages/sys-boot/lilo
> > > 
> > > ...
> > 
> > There's also 'sys-boot/elilo' for EFI systems.
> 
> The homepage returned by
> 
>    $ eix --verbose sys-boot/elilo
>    * sys-boot/elilo
>         Available versions:  ~3.16-r5
>         Homepage:            https://sourceforge.net/projects/elilo/
>         Description:         Linux boot loader for EFI-based systems such as
> IA-64 License:             GPL-2
>    $
> 
> hints that this package is no longer maintained ... :-(
> 
> Sincerely,
>   Rainer

Oh!  I haven't ever used it, but recalled its name and found it on the tree.  
I suppose if it's stable and it works, it works whether maintained or not.

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Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Dr Rainer Woitok]

Michael,

On Thursday, 2024-05-16 17:46:04 +0100, you wrote:

> ...
> > The homepage returned by
> > 
> >    $ eix --verbose sys-boot/elilo
> >    * sys-boot/elilo
> >         Available versions:  ~3.16-r5
> > ...
> >    $
> > 
> > hints that this package is no longer maintained ... :-(
> > ...
> 
> Oh!  I haven't ever used it, but recalled its name and found it on the tree.  
> I suppose if it's stable and it works, it works whether maintained or not.

Well,  the "~" ahead of the  version number says  it's non-stable.   And
considering that booting is rather hardware, firmware and kernel related
and dependent, I personally would stay off of such a package :-/

Sincerely,
  Rainer

Re: [gentoo-user] Re: Grub, gpt partitions and BIOS, not uefi thing.

[Wol]

On 28/04/2024 17:40, Grant Edwards wrote:
> On 2024-04-28, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>
>> With DOS disk lables, Grub uses empty space between the boot sector
>> and the first partition as a location to store it's core image file.
>> That empty space does not exist when using GPT disk label. When using
>> a GPT disk label, Grub requires that you need to create a "BIOS Boot"
>> or "Grub Boot" partition so that Grub has somwhere to store it's core
>> image[1].
> And it bears repeating that the bios/grub boot partition only needs to
> be 1 or 2MB in size, is _not_ formatted with a filesystem, and is
> _not_ the same as either
>
>   1) The "boot" directory where the kernel images and grubs other files
>      are installed within a Linux filesystem. [Which you still need
>      when booting in Legacy/BIOS mode.]
>
>    or
>
>   2) The UEFI partition that's formated with a FAT filesystem and used
>      in UEFI boot mode [which you don't need when booting in
>      Legacy/BIOS mode.]
>
Note that, for new installs, I generally say always create a decent 
sized partition for UEFI, so if you want to change you can, although it 
sounds like in your case it probably doesn't matter :-)


Cheers,

Wol

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Wols Lists]

On 27/04/2024 17:53, Dale wrote:
> Howdy,
> 
> I'm installing Gentoo on another old box.  To be consistent I like to
> use cgdisk, GPT I think it is called, to partition all my drives,
> regardless of size.  Thing is, Grub works differently with GPT than it
> does with the old DOS or whatever it is called, like fdisk does in the
> old days.  I did some research but still find myself in some muddy
> waters.  My take on some things I've read, I need a boot partition, not
> to be confused with the /boot for kernels, init thingys and such.  Where
> I get lost, most use gdisk.  I like cgdisk.  Before that I liked
> cfdisk.  Anyway, how do I set up that partition with cgdisk?  Any
> minimum size requirements or tiny is enough?  Does it have to be a
> specific type?  Does it need to be in a specific place?  Formatted with
> a file system?  Also, when I do grub-install, do I still point to
> /dev/sda or to /dev/sda1, if sda1 is the special boot partition?
> 
> I tried to find a step by step howto with this info but the ones I find
> either don't work or leaves me more confused.  Given that the method is
> also aging out, it's hard to find good guides.  I'd be real happy just
> to have a link to a good howto that I can make sense of.  I can save a
> copy local and even print it.  Maybe someone has some notes that will
> help.  I just need something to help clear up the muddy waters.
> 
Hmm ...

Michael's version does not ring any bells with me, and indeed my system 
is *not* set up that way. It's UEFI-capable, but at the time I didn't 
have a clue what I was doing, so the mobo dumped me into BIOS, and I 
just installed everything the old way I knew.

I do, however, have a 512MB partition configured as type "Microsoft 
basic data". This is meant to be for the UEFI partition if I get round 
to converting the system.

If you want to "suck it and see", just install grub to /dev/sda. All 
your GPT disks, by default, leave the first 2MB empty, and grub will 
stick itself in there I believe.

Cheers,
Wol

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Mickaël Bucas]

Hi

Le sam. 27 avr. 2024 à 18:53, Dale <rdalek1967@gmail.com> a écrit :
> Howdy,
>
> I'm installing Gentoo on another old box.
I was wondering how old this box could be and if it had a BIOS with
UEFI and GPT.

I didn't find a precise date for BIOS, but Wikipedia[1] shows that the
first version of Windows for x64 that can read and write GPT was
published on 2005-04-25. To boot with UEFI, a later version was
published on 2006-07-22.
I think this means most BIOSes were compatible to various degrees at this time.

So if your box is less than 20 years old, it should be OK !
I don't remember how powerful the boxes were at this time, but they
still had floppy disk drives :)

> Thanks to anyone who has a link, some notes or something.  :-D
>
> Dale
>
> :-)  :-)

Good luck

Mickaël Bucas

[1] https://en.wikipedia.org/wiki/GUID_Partition_Table#Windows:_64-bit_versions

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Mickaël Bucas wrote:
> Hi
>
> Le sam. 27 avr. 2024 à 18:53, Dale <rdalek1967@gmail.com> a écrit :
>> Howdy,
>>
>> I'm installing Gentoo on another old box.
> I was wondering how old this box could be and if it had a BIOS with
> UEFI and GPT.
>
> I didn't find a precise date for BIOS, but Wikipedia[1] shows that the
> first version of Windows for x64 that can read and write GPT was
> published on 2005-04-25. To boot with UEFI, a later version was
> published on 2006-07-22.
> I think this means most BIOSes were compatible to various degrees at this time.
>
> So if your box is less than 20 years old, it should be OK !
> I don't remember how powerful the boxes were at this time, but they
> still had floppy disk drives :)
>
>> Thanks to anyone who has a link, some notes or something.  :-D
>>
>> Dale
>>
>> :-)  :-)
> Good luck
>
> Mickaël Bucas
>
> [1] https://en.wikipedia.org/wiki/GUID_Partition_Table#Windows:_64-bit_versions
>
> .
>


Well, this thing is old enough it is only BIOS.  It's a old Dell
Inspiron 546.  It has a AMD Phenom II X4 955 CPU in it.  I upgraded it a
bit.  It is maxed out at 8GBs of memory.  No floppy but I wouldn't be
surprised to see a connector on the mobo for one tho. 

I mostly use these as rigs to do backups with but could serve as a rig
to watch TV with if my main rig goes to puter heaven.  This one is in a
case at least.  My usual NAS/backup box rig sits on a piece of plywood. 
Good ventilation during compiles tho.  ROFL 

I just got to figure out how to make it so I can login as root via ssh
again.  I set PermitRootLogin to yes in ssh config but still refuses.  I
did it on my NAS box but can't recall what else I had to do.  No
monitor, power plug or anything for it right now.  I moved it to the
kitchen table so I could hook this old Dell to the router. 

Now to see what else I can get into. 

Dale

:-)  :-) 

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Michael]

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On Sunday, 28 April 2024 13:57:23 BST Dale wrote:

> I just got to figure out how to make it so I can login as root via ssh
> again.  I set PermitRootLogin to yes in ssh config but still refuses.  I
> did it on my NAS box but can't recall what else I had to do.

Just checking the obvious, did you start sshd?

Is a port open and listening for ssh connections (use nc, telnet, nmap to find 
out).

Will it let you login as a plain user, then 'su' to run as root?

Make sure the plain user is in the wheel group.

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Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Michael wrote:
> On Sunday, 28 April 2024 13:57:23 BST Dale wrote:
>
>> I just got to figure out how to make it so I can login as root via ssh
>> again.  I set PermitRootLogin to yes in ssh config but still refuses.  I
>> did it on my NAS box but can't recall what else I had to do.
> Just checking the obvious, did you start sshd?
>
> Is a port open and listening for ssh connections (use nc, telnet, nmap to find 
> out).
>
> Will it let you login as a plain user, then 'su' to run as root?
>
> Make sure the plain user is in the wheel group.


Right now, I can login as a user then su to root, and password.  I just
can't login as root directly.  I use Dolphin and the fish thingy to
access config files etc so I can use Kwrite to edit files etc.  Thing
is, I have to login as root for some files.  No way to su to root with
Dolphin, that I know of anyway. 

I'm pretty sure I set this up on the old NAS box.  My searches shows the
PermitRootLogin set to yes should do it but I guess I missed something. 

Any ideas?  I did search old threads but only found the option above,
mentioned by Neil I think. 

Dale

:-)  :-) 

Re: [gentoo-user] Grub, gpt partitions and BIOS, not uefi thing.

[Dale]

Dale wrote:
> Michael wrote:
>> On Sunday, 28 April 2024 13:57:23 BST Dale wrote:
>>
>>> I just got to figure out how to make it so I can login as root via ssh
>>> again.  I set PermitRootLogin to yes in ssh config but still refuses.  I
>>> did it on my NAS box but can't recall what else I had to do.
>> Just checking the obvious, did you start sshd?
>>
>> Is a port open and listening for ssh connections (use nc, telnet, nmap to find 
>> out).
>>
>> Will it let you login as a plain user, then 'su' to run as root?
>>
>> Make sure the plain user is in the wheel group.
>
> Right now, I can login as a user then su to root, and password.  I just
> can't login as root directly.  I use Dolphin and the fish thingy to
> access config files etc so I can use Kwrite to edit files etc.  Thing
> is, I have to login as root for some files.  No way to su to root with
> Dolphin, that I know of anyway. 
>
> I'm pretty sure I set this up on the old NAS box.  My searches shows the
> PermitRootLogin set to yes should do it but I guess I missed something. 
>
> Any ideas?  I did search old threads but only found the option above,
> mentioned by Neil I think. 
>
> Dale
>
> :-)  :-) 
>


I figured it out.  I was editing ssh_config when I should be editing
sshd_config.  Note the "d" in there.  After doing some digging, a lot of
digging, I finally noticed that extra "d" in there.  Now it works and I
can use a file manager like Dolphin or something and fish to edit files,
move them around etc. 

Amazing how one letter can really mess things up.  ;-) 

Dale

:-)  :-)