Howto make USB boot drives

[sudodus]

@tea for one,

Thanks for the feedback

The option to enter the firmware is there in a live-only USB drive (without persistence) because mkusb clones the iso file, and it is there (in the grub.cfg file from the iso file).

This means that it will also be there is a persistent live drive made by mkusb-plug because it it almost cloning, using sed and replacing

'quiet splash' with 'persistent  '

In previous versions of Ubuntu mkusb-dus could tweak the grub.cfg from the iso file and make it work, but after some modifications of the boot structure in 20.04 LTS, it is no longer possible, so mkusb must use usb-pack-efi, and there is no call to get into the UEFI/BIOS menus there. It should be possible for me to add that feature. I will think about it ...

[tea for one]

@sudodus

I've been successfully using mkusb for a few years now.
Today was the first time using mkusb-plug.

The usb drive was created without difficulty and persistence was added during the first boot of the live session.
UEFI Firmware Settings was present in the Grub menu (exactly as you mentioned)

Thank you for your advice

Cheers

[sudodus]

Persistent live server

mkusb can clone most Linux iso files but can make persistent live drives only for Ubuntu Desktop, the community flavours (Kubuntu, Lubuntu ... Xubuntu), Debian live and some respins (distros based on Ubuntu and Debian, where the boot structure is not changed too much).

mkusb cannot make persistent live drives from Ubuntu Server iso files. But you can use the following command line for Ubuntu Live Server 20.04.3 LTS,

sed -e 's# append   initrd=/casper/initrd quiet  ---#append initrd=/casper/initrd persistent --#' -e 's#\tlinux\t/casper/vmlinuz   quiet  ---#linux\t/casper/vmlinuz persistent --#' ubuntu-20.04.3-live-server-amd64.iso > persistent-ubuntu-20.04.3-live-server-amd64.iso

Copy and paste it into a terminal window. It is very important that you get it exactly correct. Otherwise it will fail. Explanation: Editing the iso file can be done within very strict limits. The total size must be preserved and only text strings should be modified. So I replace quiet and some whitespace and one hyphen with persistent both for booting via syslinux in BIOS mode and via grub in UEFI mode.

Now you can clone the modified iso file with a cloning tool, for example mkusb-dus or mkusb-plug, for example

dus persistent-ubuntu-20.04.3-live-server-amd64.iso

The result will be a persistent live drive, that works both in BIOS mode and UEFI mode.

---

To make the persistence useful you can switch to a virtual text screen with ctrl+alt+F3 (or ctrl+alt+F4 ... and back to the menu with ctrl+alt+F1).

[sudodus]

Today (2021-10-16) I tested that mkusb can create working installer drives from a Windows 11 iso file

$ dus Windows11_InsiderPreview_Client_x64_en-us__22000.iso 
 dus 12.7.1 
live system or temporary superuser permissions
Drive that contains source file: /dev/sdb
Live drive, that is booted from: /dev/sda
Drive with a partition in fstab: /dev/nvme0n1
cands=1
sdc
Corsair_Voyager_GT_3.0
29,5G
usb
USB or memory card
p_target: target=/dev/sdc
target drive size = 32 GB
-------------------------------------------------------------------------------
live system or temporary superuser permissions
    mkusb-tow: Make Windows installer 
  source file: 'Windows11_InsiderPreview_Client_x64_en-us__22000.iso'
target device: '/dev/sdc'

MODEL            NAME FSTYPE LABEL  SIZE
Voyager GT 3.0   sdc               29,5G
umount: /dev/sdc: inte monterad.
--------------------------------------------------------------------------------
extracting the partition table with grub ...
size to extract (bytes) = 7742685184
7,21GiB 0:00:57 [ 128MiB/s] [================================================================================================================>] 100%            
----- cleanup after writing ------------------------------------------
28375 pts/2    00:00:00 watch-flush
/usr/sbin/mkusb-tow: rad 164: 28375 Avslutad                ( watch-flush "$size" "$tailfile" > /dev/null )
umount: /dev/sdc: inte monterad.
umount: /dev/sdc1: inte monterad.
umount: /dev/sdc2: inte monterad.
mount source file ...
mount: /tmp/tmp.RDf9u87oj9: VARNING: enhet skrivskyddad, monterad som endast läsbar.
mount target partition 1 ...
mount target partition 2 ...
iso file size (bytes) = 5497985024
extracting to FAT partition ...
     44,728,320 100%  146.08MB/s    0:00:00 (xfr#88, to-chk=0/104) 
    439,895,652 100%  166.53MB/s    0:00:02 (xfr#1, to-chk=0/1)
extracting to NTFS partition ...
  5,492,260,661 100%   96.67MB/s    0:00:54 (xfr#944, to-chk=0/1034)  
----- cleanup after writing ------------------------------------------
28919 pts/2    00:00:00 watch-flush
/usr/sbin/mkusb-tow: rad 164: 28919 Avslutad                ( watch-flush "$size" "$tailfile" > /dev/null )
umount: /dev/sdc: inte monterad.
umount: /dev/sdc1: inte monterad.
umount: /dev/sdc2: inte monterad.
--------------------------------------------------------------------------------
NAME MODEL            FSTYPE LABEL       MOUNTPOINT  SIZE NAME
sdc  Voyager GT 3.0                                 29,5G sdc
sdc1                  vfat   WININSTFAT              768M sdc1
sdc2                  ntfs   WinInstNtfs             6,5G sdc2
 Done :-) 
-------------------------------------------------------------------------------
clean if necessary and return
clean if necessary and return
$

[sudodus]

I have made a jammy version of ppa:mkusb/unstable and of ppa:mkusb/ppa (the stable PPA). See the attached screenshot.

[vidtek]

I have a requirement to shut the machine down and restart after returning to the premises with restricted physical access where I can't get back in until security will allow. Using a customised persistence usb stick.

I would like to edit the grub.cfg file to remove the requirement to press enter after removing media by adding "noprompt" after quiet splash.
This works when manually editing the grub options on boot, but it still requires the stick to be physically removed and re-inserted in order to boot again to the usb stick.

I have scoured the internet for answers and others have asked this question in many forums, but not a single answer. I have read and re-read man pages and how-tos until I have spots before the eyes nobody seems at be able to solve this.

My customised usb is generated with Cubic then burned by MKUSB with persistence options. The base distribution for cubic is neon-user-20211021-0945.iso

The persistence works beautifully and works for my situation. I do not want a complete install on the USB stick, I want to use persistence.

My requirement is very simple. Remove both the prompt and the need to remove the stick to reboot.

[sudodus]

@vidtek,

If you made the persistent live drive with mkusb-dus (not mkusb-plug), the file system where grub.cfg resides is writable, so you can mount the partition and edit it. Add the extra boot option 'noprompt' near the end of the line that starts with 'linux', in other words near 'persistent', and try if it works.

if you still must unplug the drive instead of only rebooting, I don't know what is the problem. Maybe it helps if you run

sudo partprobe
sync

in a terminal window and wait for a few seconds for things to settle down just before reboot.

[vidtek]

@vidtek,

If you made the persistent live drive with mkusb-dus (not mkusb-plug), the file system where grub.cfg resides is writable, so you can mount the partition and edit it. Add the extra boot option 'noprompt' near the end of the line that starts with 'linux', in other words near 'persistent', and try if it works.

if you still must unplug the drive instead of only rebooting, I don't know what is the problem. Maybe it helps if you run

sudo partprobe
sync

in a terminal window and wait for a few seconds for things to settle down just before reboot.

Thanks @sudodus, I'll give it a go and report back.
Tony.

EDIT: Well the grub.cfg edit works well, noprompt sorted, Thanks.

Unfortunately your other suggestion did not in real time. I also tried a reboot script with your suggestion:

sudo partprobe && sync && /sbin/reboot

No joy. Still requires the stick to be physically unplugged.

[vidtek]

Just realized, editing the previous post doesn't send a notification to you...doh don't get old....

Well the grub.cfg edit works well, noprompt sorted, Thanks.

Unfortunately your other suggestion did not sort the unplugging-plugging issue in real time.

I also tried a reboot script with your suggestion:
Code:

sudo partprobe && sync && /sbin/reboot

No joy. Still requires the stick to be physically unplugged/plugged.

Tony

[sudodus]

@vidtek,

I'm glad that at least one of my tips works.

I'm afraid, that the problem with unplugging might be due to things happening in the computer's early boot sequences, for example that the content of some memory locations are not reset: Old content is still there, and those memory locations are not properly cleared by the UEFI/BIOS system at reboot. If that is the case, you can test the system in different computers and it might behave differently.