Re: USB server install problem

From	Pascal Hambourg <pascal@plouf.fr.eu.org>
Newsgroups	alt.os.linux
Subject	Re: USB server install problem
Date	2019-02-06 20:17 +0100
Organization	Plouf !
Message-ID	<q3fbsa$k7v$1@saria.nerim.net> (permalink)
References	(14 earlier) <gbuc2oF9h32U1@mid.individual.net> <q3d3kd$316e$1@saria.nerim.net> <gbunbaFbruuU1@mid.individual.net> <gbupnaFcbifU1@mid.individual.net> <gburbjFcllmU1@mid.individual.net>

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Le 06/02/2019 à 02:25, Mike Easter a écrit :
> 
> When I look at sdc1 with GPartEd to set flags, its flags say boot and 
> esp.

I see. IIUC, you wanted to set the boot flag on partition sdc1.

This is where Gparted and other libparted-based software such as parted 
and partman, the Debian installer partitioning tool, get tricky because 
they treat partition types as "flags" :

1) With GPT, the "boot" flag is just an alias of the "esp" flag so you 
can only set none or both.

2) The "esp" flag is not an real flag in the traditional sense but 
indicates that the partition type is "EFI System Partition". Not to be 
confused with the "legacy_boot" flag which is more a real flag 
(attribute) but useless.

With GPT, a Linux filesystem partition should not have any "flag" at all.

> Also, GPartEd looks 'different' to me from the above.

Yes, because Gparted shows only the "real" GPT partition table 
(containing the BIOS boot and fake EFI partitions), not the protective 
MBR (containing the protective GPT partition).

> GPE says the little sdc2 part, which is in front, file system is 
> grub2core.img

Indeed the BIOS boot partition contains GRUB's core image, but it is not 
a filesystem.

> and has bios_grub flag

Similarly to the "esp" flag, the "bios_grub" flag is not a real flag but 
indicates that the partition type is "BIOS boot".

IMO, if you want to set up a USB drive for BIOS/legacy boot only and do 
not need more that 4 partitions not extending beyond 2 TiB, using a 
traditional DOS/MBR partition table would be simpler than GPT : no BIOS 
boot partition, the boot flag is really a boot flag...

On the other hand if you want to set up a USB drive for both BIOS and 
EFI boot, well, this is another story.

> And I call that parted command a 'trick'

Absolutely. It is a deviation from the GPT specification, used to work 
around a common deviation from the BIOS boot specification in broken 
firmwares.

While booting in BIOS/legacy mode, the firmware should ignore the 
partition table. It should just load the MBR sector, check the 0xAA55h 
boot signature at offset 510/1FEh and execute the boot program at offset 
0. Then the MBR boot program may or may not read the partition table and 
look for a partition with the boot flag set.

> I got a grub boot menu (which also showed me sda).

If you don't want other systems to be added to the GRUB menu, you can 
add the following line in /etc/default/grub and run update-grub (or 
update-grub2 depending on your distribution) :

# do not probe and include other systems in GRUB menu
GRUB_DISABLE_OS_PROBER=true

> The USB install runs the desktop more slowly than running a live with 
> persistence in ram.

Live systems often use a compressed read-only root filesystem such as 
squashfs, so reading from the medium is faster due to compression.

Thread

USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 08:19 -0800
  Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 08:52 -0800
  Re: USB server install problem Dan Purgert <dan@djph.net> - 2019-01-30 17:27 +0000
    Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 09:48 -0800
      Re: USB server install problem Dan Purgert <dan@djph.net> - 2019-01-30 18:15 +0000
        Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 10:25 -0800
          Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 10:45 -0800
          Re: USB server install problem "Cybe R. Wizard" <cybe_r_wizard@WizardsTower.invalid> - 2019-01-30 14:55 -0600
            Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 13:03 -0800
              Re: USB server install problem "Cybe R. Wizard" <cybe_r_wizard@WizardsTower.invalid> - 2019-01-30 15:47 -0600
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 16:00 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 16:20 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 17:01 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-01 07:00 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-01 09:01 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-01 11:04 -0800
                Re: USB server install problem Lucifer <LuciferMorningstar@bigpond.com> - 2019-02-02 06:17 +1100
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-01 11:47 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 17:19 -0800
              Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-02 08:55 +0100
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-02 01:05 -0800
                Re: USB server install problem Paul <nospam@needed.invalid> - 2019-02-02 10:50 -0500
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-02 08:39 -0800
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-02 21:38 +0100
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-03 14:01 -0800
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-04 21:58 +0100
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-04 15:33 -0800
                Re: USB server install problem Dan Purgert <dan@djph.net> - 2019-02-05 12:29 +0000
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 09:34 -0800
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-05 20:27 +0100
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-05 20:29 +0100
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 13:04 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 13:29 -0800
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-05 23:44 +0100
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-05 23:47 +0100
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 15:58 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 16:16 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 16:57 -0800
                Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-02-05 17:25 -0800
                Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-06 20:17 +0100
          Re: USB server install problem Dan Purgert <dan@djph.net> - 2019-01-30 21:44 +0000
            Re: USB server install problem Richard Kettlewell <invalid@invalid.invalid> - 2019-01-30 21:56 +0000
              Re: USB server install problem Dan Purgert <dan@djph.net> - 2019-01-30 22:04 +0000
          Re: USB server install problem Pascal Hambourg <pascal@plouf.fr.eu.org> - 2019-02-02 08:52 +0100
        Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 12:32 -0800
  Re: USB server install problem Mike Easter <MikeE@ster.invalid> - 2019-01-30 12:03 -0800

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