Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Mick]

On Friday 29 Jul 2016 12:20:14 james wrote:
> On 07/29/2016 09:27 AM, R0b0t1 wrote:
> 
> 
> 
> 
> 
> I
> OK, so I have finally switch my posting to this email. Gmane.org is dead
> for now (hence my delayed responses).
> 
> [1] https://lars.ingebrigtsen.no/2016/07/28/the-end-of-gmane/
> 
> So in one thread, I'm going to post to variety of recent posts;
> recreated since I have a new email address now anyways and just got it
> setup with gentoo-user. (sorry if this makes the thread hard to follow.
> 
>  > Neil
>  > 
>  >  It's the ESP (EF00) that can be used as /boot, EF02 is a special
>  > 
>  > partition that should exist but not be used.
> 
> Agreed. The posted example partition tables (PT) were just an attempt
> to motivate any respondant to post an actual (PT) presented by whatever
> tool so I could actually see what I'm trying to drive to. Soon, later
> tonight or tomorrow, I'll post an actual attempt from recovered failures.
> 
>  > Tomh
>  > The OP wants a partition scheme for both "standard" and efi firmware,
>  > so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).
> 
> Yes, this is a key point.
> 
>  > The OP wanted the EF02 to be mounted as "/boot" so it has to be
>  > larger than 100MB in order to accomodate multiple kernels (and
>  > possibly initramfs "thingies" as they're sometimes called here).
>  > 
>  > It's the ESP (EF00) that can be used as /boot, EF02 is a
>  > special partition that should exist but not be used.
> 
> OK, my problem is I do not know exactly what this looks like. I am
> assuming I can do it all with gdisk (which is gptfdisk right)?
> 
> So this is just a starting point of what the PT & fstab cold look like
> 
> Number  Start   End SizeType File system Flags
>   1  1049kB  211MB   210MB   primary  ext2boot
>   2  211MB   139GB   138GB   primary  linux-swap(v1)
>   3  139GB   952GB   813GB   primary  ext4
>   4  952GB   2000GB  1049GB  primary  ext4
> 
> corresponding fstab::
> 
> /dev/sda1   /bootext2defaults,noatime 0 2
> /dev/sda2   none swapsw 0 0
> /dev/sda3   /  ext4defaults,noatime 0 1
> /dev/sda4   /usr/local   ext4defaults,noatime 0 1
> 
>  > David Haller
>  > You'd have to get rid of one of those partitions (I'd say /boot).
> 
> OK, I was already thinking about placing /boot under '/' anyway, as
> many of the stage-4 images I will be using in the auto-image installs
> are commonly found as using just 2 partitions anyway ('/' and swap)
> 
> The '/usr/local' will be optional depending on disk size and available
> space to provide this third partition. /usr/local will not be needed for
> boot(strap) and can be mounted after the systems is up. So /boot
> is part of / now.
> 
>  > Mick
>  > It seems you did not use gdisk or a late version of parted to created
>  > the partition table?  Modern partition tools align the logical and
>  > physical sectors to 4096B.
> 
> Yep, I just 'dogged' the PT hoping someone would create and post what it
> should look like, or copy/paste a correct example from somewhere. Sorry
> 
>  >> 1  1049kB  211MB   210MB   primary  ext2boot
>  > 
>  > Instead of ext2 follow the guide for creating a FAT fs partition with
>  > an EF00 partition type.
>  > James should set the boot flag in the partition table for /dev/sda1
>  > and mount it under /boot (or /boot/EFI) in fstab.
> 
> I'm going to do away with a separate /boot for now and 'boot' partition
> will be moved under /.
> 
>  > R0b0t1
>  > 
>  > > It seems you did not use gdisk or a late version of parted to
>  > 
>  > created the partition table?  Modern partition tools align the
>  > logical and physical sectors to 4096B.
>  > 
>  > It can be changed. SSDs are best used with 512B sectors. But, err...
> 
> Well, proper alignment was automatically taken care of with newer tools?
> That sort of perfromance issue is also critical. Eventuall, SSD and usb3
> mmc and all sorts of other media will be used, depending on the embedded
> board's supported interface mix that will work with the vendor's (board)
> bootstrap code to bring up linux.
> 
>  > The protective MBR can point to another one and you can select which
>  > GPT partitions are in it. But that's getting into some rube goldberg
>  > action.
> 
> Is this true if one is using grub-legacy?
> 
> While I'm at it (gentoo specific) what is the difference in
> sys-boot/grub-static (0.96-r1 to  0.97-r12) and sys-boot/grub (0.97-r16)
> in slot zero?
> 
> I'm assuming that sys-boot/grub-2.02_beta2-r9++ is all grub-2 with
> current enhancements.
> 
> 
> I do appreciate all the inputs, and appologize again for the
> transitioning emails, complicated by the demise of gmane.org (my fav
> reading/posting for gentoo-user).
> 
> I'm going to post back as soon as I get an actually 2T disk setup with
> all of this advise, just to check what folks think and eventually with
> the results of booting a variety of 

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[james]

On 07/29/2016 09:27 AM, R0b0t1 wrote:

>
>
>

I
OK, so I have finally switch my posting to this email. Gmane.org is dead 
for now (hence my delayed responses).


[1] https://lars.ingebrigtsen.no/2016/07/28/the-end-of-gmane/

So in one thread, I'm going to post to variety of recent posts; 
recreated since I have a new email address now anyways and just got it

setup with gentoo-user. (sorry if this makes the thread hard to follow.

> Neil
>  It's the ESP (EF00) that can be used as /boot, EF02 is a special
> partition that should exist but not be used.

Agreed. The posted example partition tables (PT) were just an attempt
to motivate any respondant to post an actual (PT) presented by whatever
tool so I could actually see what I'm trying to drive to. Soon, later 
tonight or tomorrow, I'll post an actual attempt from recovered failures.


> Tomh
> The OP wants a partition scheme for both "standard" and efi firmware,
> so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).


Yes, this is a key point.

> The OP wanted the EF02 to be mounted as "/boot" so it has to be
> larger than 100MB in order to accomodate multiple kernels (and
> possibly initramfs "thingies" as they're sometimes called here).

> It's the ESP (EF00) that can be used as /boot, EF02 is a
> special partition that should exist but not be used.

OK, my problem is I do not know exactly what this looks like. I am
assuming I can do it all with gdisk (which is gptfdisk right)?

So this is just a starting point of what the PT & fstab cold look like

Number  Start   End SizeType File system Flags
 1  1049kB  211MB   210MB   primary  ext2boot
 2  211MB   139GB   138GB   primary  linux-swap(v1)
 3  139GB   952GB   813GB   primary  ext4
 4  952GB   2000GB  1049GB  primary  ext4

corresponding fstab::

/dev/sda1   /bootext2defaults,noatime 0 2
/dev/sda2   none swapsw   0 0
/dev/sda3   /ext4defaults,noatime 0 1
/dev/sda4   /usr/local   ext4defaults,noatime 0 1


> David Haller
> You'd have to get rid of one of those partitions (I'd say /boot).

OK, I was already thinking about placing /boot under '/' anyway, as
many of the stage-4 images I will be using in the auto-image installs
are commonly found as using just 2 partitions anyway ('/' and swap)

The '/usr/local' will be optional depending on disk size and available 
space to provide this third partition. /usr/local will not be needed for 
boot(strap) and can be mounted after the systems is up. So /boot

is part of / now.

> Mick
> It seems you did not use gdisk or a late version of parted to created
> the partition table?  Modern partition tools align the logical and
> physical sectors to 4096B.

Yep, I just 'dogged' the PT hoping someone would create and post what it
should look like, or copy/paste a correct example from somewhere. Sorry

>> 1  1049kB  211MB   210MB   primary  ext2boot

> Instead of ext2 follow the guide for creating a FAT fs partition with
> an EF00 partition type.
> James should set the boot flag in the partition table for /dev/sda1
> and mount it under /boot (or /boot/EFI) in fstab.

I'm going to do away with a separate /boot for now and 'boot' partition 
will be moved under /.


> R0b0t1
> > It seems you did not use gdisk or a late version of parted to
> created the partition table?  Modern partition tools align the
> logical and physical sectors to 4096B.

> It can be changed. SSDs are best used with 512B sectors. But, err...

Well, proper alignment was automatically taken care of with newer tools?
That sort of perfromance issue is also critical. Eventuall, SSD and usb3
mmc and all sorts of other media will be used, depending on the embedded
board's supported interface mix that will work with the vendor's (board) 
bootstrap code to bring up linux.


> The protective MBR can point to another one and you can select which
> GPT partitions are in it. But that's getting into some rube goldberg
> action.

Is this true if one is using grub-legacy?

While I'm at it (gentoo specific) what is the difference in 
sys-boot/grub-static (0.96-r1 to  0.97-r12) and sys-boot/grub (0.97-r16)

in slot zero?

I'm assuming that sys-boot/grub-2.02_beta2-r9++ is all grub-2 with 
current enhancements.



I do appreciate all the inputs, and appologize again for the 
transitioning emails, complicated by the demise of gmane.org (my fav 
reading/posting for gentoo-user).


I'm going to post back as soon as I get an actually 2T disk setup with
all of this advise, just to check what folks think and eventually with
the results of booting a variety of mbr systems (efi and newer embedded 
systems as they are purchased.)


I have a few SSD to experiment with now and may try some usb devices
after the spinning rust PT is happy.


James

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[R0b0t1]

Fri, Jul 29, 2016 at 12:41 AM, Mick  wrote:
> On Thursday 28 Jul 2016 18:36:52 David Haller wrote:
>> Hello,
>>
>> On Tue, 26 Jul 2016, James wrote:
>> [..]
>>
>> Well, the best I found is this on the gdisk homepage:
>> http://www.rodsbooks.com/gdisk/hybrid.html
>>
>> Basically, you shouldn't. The article tackles most aspects and
>> pitfalls.
>>
>> [..]
>> > #parted -l /dev/sda
>> > Model: ATA WDC WD20EARX-00P (scsi)
>> > Disk /dev/sda: 2000GB
>> > Sector size (logical/physical): 512B/4096B
>  ^^
> It seems you did not use gdisk or a late version of parted to created the
> partition table?  Modern partition tools align the logical and physical
> sectors to 4096B.

It can be changed. SSDs are best used with 512B sectors. But, err...

> James should set the boot flag in the partition table for /dev/sda1 and mount
> it under /boot (or /boot/EFI) in fstab.
>
>> By following the example in the above webpage, it worked on a file.
>> But it is rather sure to fail if you need more than 3 partitions (as
>> one is taken for the GPT, that leaves 3 more primary ones in the MBR
>> and logical partitions is doomed to fail.
>>

The protective MBR can point to another one and you can select which
GPT partitions are in it. But that's getting into some rube goldberg
action.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Mick]

On Thursday 28 Jul 2016 18:36:52 David Haller wrote:
> Hello,
> 
> On Tue, 26 Jul 2016, James wrote:
> [..]
> 
> Well, the best I found is this on the gdisk homepage:
> http://www.rodsbooks.com/gdisk/hybrid.html
> 
> Basically, you shouldn't. The article tackles most aspects and
> pitfalls.
> 
> [..]
> > #parted -l /dev/sda
> > Model: ATA WDC WD20EARX-00P (scsi)
> > Disk /dev/sda: 2000GB
> > Sector size (logical/physical): 512B/4096B
 ^^
It seems you did not use gdisk or a late version of parted to created the 
partition table?  Modern partition tools align the logical and physical 
sectors to 4096B.

> > Number  Start   End SizeType File system Flags
> > 1  1049kB  211MB   210MB   primary  ext2boot

Instead of ext2 follow the guide for creating a FAT fs partition with an EF00 
partition type.


> > 2  211MB   139GB   138GB   primary  linux-swap(v1)
> > 3  139GB   952GB   813GB   primary  ext4
> > 4  952GB   2000GB  1049GB  primary  ext4
> 
> You'd have to get rid of one of those partitions (I'd say /boot).

James should set the boot flag in the partition table for /dev/sda1 and mount 
it under /boot (or /boot/EFI) in fstab.


> By following the example in the above webpage, it worked on a file.
> But it is rather sure to fail if you need more than 3 partitions (as
> one is taken for the GPT, that leaves 3 more primary ones in the MBR
> and logical partitions is doomed to fail.
> 
> HTH,
> -dnh

-- 
Regards,
Mick

signature.asc
Description: This is a digitally signed message part.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[David Haller]

Hello,

On Tue, 26 Jul 2016, James wrote:
[..]

Well, the best I found is this on the gdisk homepage:
http://www.rodsbooks.com/gdisk/hybrid.html

Basically, you shouldn't. The article tackles most aspects and
pitfalls.

[..]
>Number  Start   End SizeType File system Flags
> 1  1049kB  211MB   210MB   primary  ext2boot
> 2  211MB   139GB   138GB   primary  linux-swap(v1)
> 3  139GB   952GB   813GB   primary  ext4
> 4  952GB   2000GB  1049GB  primary  ext4

You'd have to get rid of one of those partitions (I'd say /boot).

By following the example in the above webpage, it worked on a file.
But it is rather sure to fail if you need more than 3 partitions (as
one is taken for the GPT, that leaves 3 more primary ones in the MBR
and logical partitions is doomed to fail.

HTH,
-dnh

-- 
"Cynical" is a term invented by optimists to describe realists.
-- Gregory Benford

[gentoo-user] Re: MBR & GPT dual compliant format

[James]

Tom H  gmail.com> writes:



> > > I you're using GTP but want to stick to MBR, then you create 1MB
> > > partition to hold the boot loader, then /boot and the rest.

Hello,

The idea is to be able to set up a batch of 2T+ disks now and in the future,
all pretty much the same (generic) layout for both bios based systems and
efi systems, so the drives do not have to have the partition tables changed.
A standard partition scheme will put the extra disk space (according to
size) all into the /usr/local partition. A wide variety of File systems will
be imposed on the /usr/local and maybe the other 
(3) partitions:: /; /boot/: /usr File systems can change, especially what 
is on /usr/local. Distributed file systems will be routinely tested too.
All drive will keep the default boot-drive partitions, maybe for multiple
different systems/kernels (all linux though) so if a drive is to be used
as a non-boot drive, the some of the partitions may not be mounted for a
particular experiment (cluster/codes) configuration. I hope this clearly
states the ultimate goal so the myriad of bios systems I have can be used,
but also the same scheme with many new embedded and efi based systems with
many different processors (and Soc) on the mobo. Much of the testing will
be only changing codes on gentoo systems. But there will be time when a
*buntu cluster is tested, keeping all the hardware identically the same
as a gentoo reference run.


Testing a wide (wild?) variety of clusters will constantly mix and match
disks to various motherboards and embedded systems (with sata) interfaces.

So what I'm looking for is for someone to edit the partition table I
post below, so that it looks like what I need. I have tons of verbiage of
what to do, but not a single, example  partition table of what it would
actually look like (perhaps as viewed by several different (CLI)
partitioning tools (gdisk, fdisk, parted) to highlight the minutia
of the partition table.. A companion fstab (ext2/3/4) that works, would be
keenly appreciated. I only ask because I have failed at this effort in the
past and currently.

> > > About the 100MB EFI-partition: it's a Microsoft recommendation:
> > > https://wiki.archlinux.org/index.php/EFI_System_Partition, read the
> > > "create the partition" section.

I intend to only use grub-legacy for this effort. But, some explanation
as to when I would absolutely need grub-2, if that case even exists, would
be keen knowledge to have. Some other common distros, when I cannot get
something to work with gentoo, would be alpine and arch, when a gentoo
solution evades me. I might even spin up a complete (DC/OS) like mesosphere
or CoreOS for benchmarking. The idea is to take a small cluster and spin it
up with several different (cluster centric) solutions to problems and
measure the performance in a variety of test surveys. The suspected outcome
is that gentoo  that is minimized and optimize (including kernel and
compiler and framework tweaks), is always the performance king of the
clusters. At this point my evidence is anecdotal and not 'publishable
grade'.  I want to be fair to the bloated vendor communities and have a
consistent hardware platform, for these test-surveys.

Additionally, searching out details of kernel tweaks that optimize 
a particular problem-set of cluster-code-solutions is also of keen interest
to me.

> > Please bottom-post.

Agreed.


> > The OP wants a partition scheme for both "standard" and efi firmware,
> > so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).

Guys, the drives are 2T and larger, so the ridiculously largest partition
size needed in the worst case scenario, that works as specd-above is the
best answer.


> > The OP wanted the EF02 to be mounted as "/boot" so it has to be larger
> > than 100MB in order to accommodate multiple kernels (and possibly
> > initramfs "thingies" as they're sometimes called here).

I have never had a linux system with less than 6 kernels, often many more,
just for that one system. I use to hack kernels for breakfast (2.2-early
3.x) so yes tons of space for kernel hackery is warranted. All kernels will
also be archived to a separate backup machine/system. Kernel tweaks (as
found in kernel sources, as well as many codes in the wild, pretty much
means that endless kernel tests are warranted and that does require gigs of
disk space and organized back end storage and notations.


> Then the OP is lucky as the handbook describes this exact scheme the OP 
> wants. Only one adjustment should be considered - I would recommend 
> around 500 MB for /boot if the OP wants to use multiple systems and if 
> disk space is of no special concern.

I was think 2G for /boot. Here is a common partition table and subsequent
fstab that folks are encourage to edit as to what they would use for this
universal partitioning scheme.


#parted -l /dev/sda
Model: ATA WDC WD20EARX-00P (scsi)
Disk /dev/sda: 2000GB
Sector size (logical/physical): 512B/4096B
Partition 

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Tom H]

On Tue, Jul 26, 2016 at 8:10 AM, Artur Zych  wrote:
> 26 lip 2016 10:29 "Tom H"  napisał(a):
>> On Tue, Jul 26, 2016 at 2:56 AM, Artur Zych  wrote:
>>>
>>> If you're using GPT disk and want to use uefi then you can just create
>>> one efi partition (should be around 200-500mb (depends if you're
>>> planning on using multiple systems on the same disk) - this will hold
>>> .efi files for all your systems as well as the bootloader.
>>>
>>> I you're using GTP but want to stick to MBR, then you create 1MB
>>> partition to hold the boot loader, then /boot and the rest.
>>>
>>> About the 100MB EFI-partition: it's a Microsoft recommendation:
>>> https://wiki.archlinux.org/index.php/EFI_System_Partition, read the
>>> "create the partition" section.
>>
>> Please bottom-post.
>>
>> The OP wants a partition scheme for both "standard" and efi firmware,
>> so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).
>>
>> The OP wanted the EF02 to be mounted as "/boot" so it has to be larger
>> than 100MB in order to accomodate multiple kernels (and possibly
>> initramfs "thingies" as they're sometimes called here).
>
> Then the OP is lucky as the handbook describes this exact scheme the OP
> wants. Only one adjusment should be considered - I would recommend around
> 500 MB for /boot if the OP wants to use multiple systems and if
> disk space is of no special concern.

I haven't looked at the handbook for a long time but I hope that it
doesn't recommend creating both of these partitions by default. It
doesn't make sense for a default setup.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Tom H]

On Tue, Jul 26, 2016 at 9:54 AM, Neil Bothwick  wrote:
> On 26 July 2016 10:29:08 CEST, Tom H  wrote:
>> On Tue, Jul 26, 2016 at 2:56 AM, Artur Zych  wrote:
>>>
>>> If you're using GPT disk and want to use uefi then you can just create
>>> one efi partition (should be around 200-500mb (depends if you're
>>> planning on using multiple systems on the same disk) - this will hold
>>> .efi files for all your systems as well as the bootloader.
>>>
>>> I you're using GTP but want to stick to MBR, then you create 1MB
>>> partition to hold the boot loader, then /boot and the rest.
>>>
>>> About the 100MB EFI-partition: it's a Microsoft recommendation:
>>> https://wiki.archlinux.org/index.php/EFI_System_Partition, read the
>>> "create the partition" section.
>>
>> Please bottom-post.
>>
>> The OP wants a partition scheme for both "standard" and efi firmware,
>> so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).
>>
>> The OP wanted the EF02 to be mounted as "/boot" so it has to be
>> larger than 100MB in order to accomodate multiple kernels (and
>> possibly initramfs "thingies" as they're sometimes called here).
>
> It's the ESP (EF00) that can be used as /boot, EF02 is a special
> partition that should exist but not be used.

Good catch.

I no longer have my initial email but it looks like I also screwed up
my first para and emailed it unfinished; somehow.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Neil Bothwick]

On 26 July 2016 10:29:08 CEST, Tom H  wrote:
> On Tue, Jul 26, 2016 at 2:56 AM, Artur Zych 
> wrote:
> >
> > If you're using GPT disk and want to use uefi then you can just
> create
> > one efi partition (should be around 200-500mb (depends if you're
> > planning on using multiple systems on the same disk) - this will
> hold
> > .efi files for all your systems as well as the bootloader.
> >
> > I you're using GTP but want to stick to MBR, then you create 1MB
> > partition to hold the boot loader, then /boot and the rest.
> >
> > About the 100MB EFI-partition: it's a Microsoft recommendation:
> > https://wiki.archlinux.org/index.php/EFI_System_Partition, read the
> > "create the partition" section.
> 
> Please bottom-post.
> 
> The OP wants a partition scheme for both "standard" and efi firmware,
> so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).
> 
> The OP wanted the EF02 to be mounted as "/boot" so it has to be larger
> than 100MB in order to accomodate multiple kernels (and possibly
> initramfs "thingies" as they're sometimes called here).

It's the ESP (EF00)  that can be used as /boot, EF02 is a special partition 
that should exist but not be used. 
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Artur Zych]

26 lip 2016 10:29 "Tom H"  napisał(a):
>
> On Tue, Jul 26, 2016 at 2:56 AM, Artur Zych  wrote:
> >
> > If you're using GPT disk and want to use uefi then you can just create
> > one efi partition (should be around 200-500mb (depends if you're
> > planning on using multiple systems on the same disk) - this will hold
> > .efi files for all your systems as well as the bootloader.
> >
> > I you're using GTP but want to stick to MBR, then you create 1MB
> > partition to hold the boot loader, then /boot and the rest.
> >
> > About the 100MB EFI-partition: it's a Microsoft recommendation:
> > https://wiki.archlinux.org/index.php/EFI_System_Partition, read the
> > "create the partition" section.
>
> Please bottom-post.
>
> The OP wants a partition scheme for both "standard" and efi firmware,
> so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).
>
> The OP wanted the EF02 to be mounted as "/boot" so it has to be larger
> than 100MB in order to accomodate multiple kernels (and possibly
> initramfs "thingies" as they're sometimes called here).
>
Then the OP is lucky as the handbook describes this exact scheme the OP
wants. Only one adjusment should be considered - I would recommend around
500 MB for /boot if the OP wants to use multiple systems and if
disk space is of no special concern.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Tom H]

On Tue, Jul 26, 2016 at 2:56 AM, Artur Zych  wrote:
>
> If you're using GPT disk and want to use uefi then you can just create
> one efi partition (should be around 200-500mb (depends if you're
> planning on using multiple systems on the same disk) - this will hold
> .efi files for all your systems as well as the bootloader.
>
> I you're using GTP but want to stick to MBR, then you create 1MB
> partition to hold the boot loader, then /boot and the rest.
>
> About the 100MB EFI-partition: it's a Microsoft recommendation:
> https://wiki.archlinux.org/index.php/EFI_System_Partition, read the
> "create the partition" section.

Please bottom-post.

The OP wants a partition scheme for both "standard" and efi firmware,
so he wants an EF02 (gdisk name) of 1MB and an EF00 (also gdisk name).

The OP wanted the EF02 to be mounted as "/boot" so it has to be larger
than 100MB in order to accomodate multiple kernels (and possibly
initramfs "thingies" as they're sometimes called here).

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Artur Zych]

Hi,

If you're using GPT disk and want to use uefi then you can just create one
efi partition (should be around 200-500mb (depends if you're planning on
using multiple systems on the same disk) - this will hold .efi files for
all your systems as well as the bootloader.
I you're using GTP but want to stick to MBR, then you create 1MB partition
to hold the boot loader, then /boot and the rest.

About the 100MB EFI-partition: it's a Microsoft recommendation:
https://wiki.archlinux.org/index.php/EFI_System_Partition, read the "create
the partition" section.

Regards,
-az

2016-07-26 7:55 GMT+02:00 Neil Bothwick :

> On 25 July 2016 13:36:24 GMT-04:00, David Haller 
> wrote:
>>
>> Hello,
>>
>> On Sun, 24 Jul 2016, Neil Bothwick wrote:
>>
>>> Step 1: Use gdisk to create a 1M partition at the start of the disk.
>>> Step 2: Set its type to EF02
>>>
>>
>> I think the EFI-partition should be 100MiB.
>>
>> -dnh
>>
>>
> The ESP (EF00) can be whatever size you need, mine is 1GB. Bit the
> compatibility EF02 partition needs be inly 1MB.
> --
> Sent from my Android phone with K-9 Mail. Please excuse my brevity.
>

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Neil Bothwick]

On 25 July 2016 13:36:24 GMT-04:00, David Haller  wrote:
> Hello,
> 
> On Sun, 24 Jul 2016, Neil Bothwick wrote:
> >Step 1: Use gdisk to create a 1M partition at the start of the disk. 
> >Step 2: Set its type to EF02
> 
> I think the EFI-partition should be 100MiB.
> 
> -dnh
> 
> -- 
> Like all software  sucks, but by knowing how it works it is possible
> to make it suck in new and exciting ways.   -- S. M. Valstad

The ESP (EF00) can be whatever size you need, mine is 1GB. Bit the 
compatibility EF02 partition needs be inly 1MB.
-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[David Haller]

Hello,

On Sun, 24 Jul 2016, Neil Bothwick wrote:
>Step 1: Use gdisk to create a 1M partition at the start of the disk. 
>Step 2: Set its type to EF02

I think the EFI-partition should be 100MiB.

-dnh

-- 
Like all software  sucks, but by knowing how it works it is possible
to make it suck in new and exciting ways.   -- S. M. Valstad

Re: [gentoo-user] Re: MBR & GPT dual compliant format

[Neil Bothwick]

On 23 July 2016 04:29:50 CEST, James  wrote:
> R0b0t1  gmail.com> writes:
> 
> > On Jul 22, 2016 5:43 PM, "Neil Bothwick"  digimed.co.uk>
> wrote:
> > > I take it this is a limitation of Apple's firmware as I have set
> up a
> > > number of uUEFI systems and never had to do this.
> 
> > It is.
> 
> 
> There is another document that talks in depth about the issue,
> although
> it was centric to using gpt disk on a bios world that was slowly
> moving
> to efi [1].
> 
> 
> [1] http://mjg59.dreamwidth.org/8035.html
> 
> Here is the essence::
> "But most BIOSes (and most older operating systems) don't understand
> GPT, so
> plugging in a GPT-partitioned disk would result in the system
> believing that
> the drive was uninitialised. This is avoided by specifying a
> protective MBR.
> This is a valid MBR partition table with a single partition covering
> the
> entire disk (or the first 2.2TB of the disk if it's larger than that)
> and
> the partition type set to 0xee ("GPT Protective"). GPT-unaware BIOSes
> and
> operating systems will see a partition they don't understand and
> simply
> ignore it."
> 
> 
> I do not know how to set up a 'protective MBR', that's my issue. This
> reference goes on to talk about how the code was written for parted
> but
> never made the permanent status. It sure would fix a lot of
> installation
> issues among many different distros. An excellent read, if anyone has
> the
> time. Me, I'm going to use this method::
> 
> 1. First, write an example of what the partition table should look
> like.
> 
> 2. Figure out the separate tools & sequences to achieve the final
> result.
> 
> 3. Document the steps so they are clearly available for our community.
> 
> 4. Hope that one of the devs/hackers spins a patched version of a
> "parted"
> formatting tool to achieve this ability, system-rescue seems  to be
> the best
> home. Or if a patched parted only lives in an overlay, that would ease
> quite
> a lot of pain for many folks as in my research experience, setting up
> the
> disk partitioning schemes is the toughest part of an installation
> these
> days. This duality of disk usage  is critical to my cluster testing
> schema.
> I'll  also have a variety of bootstap codes to deal with from various
> embedded systems, in addition to commonly purchased hardware
> platforms, so
> extending the formatting to other forms of storage, in a consistent
> and
> generic way, provides an even greater appeal.
> 
> From the same doc::
> "It violates the spec and it confuses the majority of partitioning
> tools. I
> wrote some code to make parted do it at one point, but I don't believe
> it
> was ever merged. It's very difficult to make it work well. "
> 
> They discuss also some of the MAC family of issues and explain why
> macs
> still suffer from this malaise. I hope that code is still around
> 
> 
> Thanks for all the advice and help.
> James

Step 1: Use gdisk to create a 1M partition at the start of the disk. 
Step 2: Set its type to EF02
Step 3: There is no step 3,don't overcomplicate things, all the information you 
need has already been posted. 

-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

[gentoo-user] Re: MBR & GPT dual compliant format

[James]

R0b0t1  gmail.com> writes:

> On Jul 22, 2016 5:43 PM, "Neil Bothwick"  digimed.co.uk> wrote:
> > I take it this is a limitation of Apple's firmware as I have set up a
> > number of uUEFI systems and never had to do this.

> It is.


There is another document that talks in depth about the issue, although
it was centric to using gpt disk on a bios world that was slowly moving
to efi [1].


[1] http://mjg59.dreamwidth.org/8035.html

Here is the essence::
"But most BIOSes (and most older operating systems) don't understand GPT, so
plugging in a GPT-partitioned disk would result in the system believing that
the drive was uninitialised. This is avoided by specifying a protective MBR.
This is a valid MBR partition table with a single partition covering the
entire disk (or the first 2.2TB of the disk if it's larger than that) and
the partition type set to 0xee ("GPT Protective"). GPT-unaware BIOSes and
operating systems will see a partition they don't understand and simply
ignore it."


I do not know how to set up a 'protective MBR', that's my issue. This
reference goes on to talk about how the code was written for parted but
never made the permanent status. It sure would fix a lot of installation
issues among many different distros. An excellent read, if anyone has the
time. Me, I'm going to use this method::

1. First, write an example of what the partition table should look like.

2. Figure out the separate tools & sequences to achieve the final result.

3. Document the steps so they are clearly available for our community.

4. Hope that one of the devs/hackers spins a patched version of a "parted"
formatting tool to achieve this ability, system-rescue seems  to be the best
home. Or if a patched parted only lives in an overlay, that would ease quite
a lot of pain for many folks as in my research experience, setting up the
disk partitioning schemes is the toughest part of an installation these
days. This duality of disk usage  is critical to my cluster testing schema.
I'll  also have a variety of bootstap codes to deal with from various
embedded systems, in addition to commonly purchased hardware platforms, so
extending the formatting to other forms of storage, in a consistent and
generic way, provides an even greater appeal.

>From the same doc::
"It violates the spec and it confuses the majority of partitioning tools. I
wrote some code to make parted do it at one point, but I don't believe it
was ever merged. It's very difficult to make it work well. "

They discuss also some of the MAC family of issues and explain why macs
still suffer from this malaise. I hope that code is still around


Thanks for all the advice and help.
James