Must a 20.04 live-boot installer be UEFI/GPT to create a UEFI/GPT SSD install?

[watchpocket]

I'm trying to create a UEFI/GPT live-boot USB drive to install 20.04 in UEFI/GPT mode.

I have a USB drive (with no .iso on it) that is formatted thusly:

Its partition table is GPT.

It has a 200 MB empty space at the beginning;

It has a 1 GB, fat32 ESP partition (sdc1) with boot and esp flags enabled;
(this partition already has some files and folders in it (from a previous attempt): boot folder, casper folder, EFI folder, README.diskdefines file, and .disk folder)

This flash drive also has a 6 GB, ext4 partition (sdc2) where the 20.04 installer will go; and a 2 MB empty space at the end.

I just tried to use Unetbootin to install an ubuntu-mate-20.04.1-desktop-amd64.iso onto sdc2, and it hung. (It is an EFI image.)

I have a feeling that this is not the right way (or right location) to put the .iso on this USB drive.

Because if I install the .iso onto sdc2, I don't know that the boot files will detect the ESP partition (sdc1).

But, as indicated above, I already have boot files in the ESP partition from a previous attempt. Should I delete them before running Unetbootin to put the .iso on the flash drive to make it live-boot?

Because my last attempt hung, I now have some of the iso's files on the flash drive, but I'm thinking I should delete them and start over. However, it appears that Unetbootin only allows to install the .iso on either sdc1 or sdc2.

(I was thinking that if I could choose just sdc, that Unetbootin would detect the ESP partition I already have, and install the boot files there.

How can I get the .iso onto a flash drive so that I have a working UEFI/GPT installer, ready to create a UEFI/GPT SSD install?

[oldfred]

Some installers use dd (or dd hidden under the hood) to create an unpartitioned hybrid DVD/flash drive installer.
Others extract the ISO to a FAT32 formatted partition. If BIOS boot also requried, they add a BIOS boot loader to flash drive.
It is possible to use grub2's loopmount command to directly boot many ISO. ISO has to be configured for grub's boot. You have to have grub and manually create the correct boot stanza to boot the ISO which can be in any partition.

Lots of info on USB boot for installing
https://help.ubuntu.com/community/Installation/iso2usb
https://help.ubuntu.com/community/In...n/FromUSBStick
Ubuntu install guide - multiple ways to create live installer to flash drive
https://help.ubuntu.com/community/Installation

Tools often recommended:
rufus,mkusb, iso2usb,unetbooting, balena etcher

[C.S.Cameron]

Does the USB currently boot to a GRUB menu?
If so then you can put your ISO on your ext4 sdc partition and add a menuitem for it in sdc1's grub.cfg.

See: https://askubuntu.com/questions/1251...251782#1251782

It might be easier to overwrite the USB with a Rufus UEFI install which will guarantee an UEFI install to the HDD if Partition scheme: GPT is used with Target system UEFI (non CSM) options.

[watchpocket]

So far what I've done is, I've taken another (8 GB) USB flash drive (different than the one I was using in my first post), and created a bootable Ubuntu UEFI (I hope UEFI) USB drive, according to this tutorial, which uses the "Disk" utility.

(Elsewhere, Rod Smith, btw, advises against using Unetbootin to create a UEFI install media.)

This boots to a grub menu where I can choose "Try Ubuntu before Installing." I select that, and it does boot into the full 20.04 interface. But before that happens, I get a worrisome error message at the top of a black screen:

"4.7413[a few other digits here] Initramfs: packing failed, decoding failed"

But then it does go ahead and boot into the trial 20.04. I noticed in gparted that this USB drive's partition table is msdos. Does the USB drive's partition table need to be GPT to successfully install onto an SSD in full UEFI/GPT mode?

Given that error message, I wonder if I should try to do an installation to my SSD with this USB drive?

I may just want to start over and re-create a USB installer without such errors.

[oldfred]

I now only use gpt for everything. But have used gpt for all new drives since about 2010.

Some installers only create a BIOS boot if MBR and only UEFI if gpt.
Most can be either partitioning and boot in either mode. It depends on install tool used. Not sure about Disks. Not seen many use it. I only use Disks to add labels to partitions as have seen it not do things as well as gparted for partitioning.

You may need to check that download was correct. But now it verifies as part of boot of live installer. That may have been issue?

md5sum (older versions) or sha256sum (new versions)
https://help.ubuntu.com/community/HowToSHA256SUM
https://ubuntuforums.org/showthread.php?t=2449090
https://help.ubuntu.com/community/BootOptions
https://help.ubuntu.com/community/HowToMD5SUM &
https://help.ubuntu.com/community/UbuntuHashes

[sudodus]

The advice how to make the USB boot drive depends on your answer to the following questions:

0. What is the size of the USB drive? (From your description I think 8 GB, but I may be wrong.)

1a. Are you making the USB boot drive in Ubuntu or some other linux distro?
1b. Or are you making the USB boot drive in Windows or in MacOS?

2a. Is it enough to get a live (live-only) USB boot drive, that can boot in UEFI mode (and run live sessions and install Ubuntu)?
2b. Or do you need a live system, that can store data past shutdown/reboot, a persistent live drive?
2c. Or do you want an installed system (like installed in an internal drive, but in a USB drive)?

3a. Is it enough, that the drive can boot in UEFI mode?
3b. Or should it boot also in BIOS mode (alias CSM alias legacy mode)?

Edit:

"4.7413[a few other digits here] Initramfs: packing failed, decoding failed"

This output can be printed but the live session will work anyway. You need not worry too much about it (in a live session).

[watchpocket]

The advice how to make the USB boot drive depends on your answer to the following questions:
0. What is the size of the USB drive? (From your description I think 8 GB, but I may be wrong.)

Correct. I'm using an 8 GB USB drive. I've been led to believe that using a smaller-capacity USB drive for this install might not provide enough space for creating a functioning live-boot drive, at least in this instance.

1a. Are you making the USB boot drive in Ubuntu or some other linux distro?

I am trying to creating a USB boot drive in Ubuntu-MATE 18.04.4 on a desktop workstation.

That workstation has 2 internal one-terabyte SSDs. One of those SSDs has the 18.04 install (which is my current working system and which boots via BIOS); the other SSD is just for storage, not for booting into an OS.

1b. Or are you making the USB boot drive in Windows or in MacOS?

No Windows, ever. No MacOS. I do not use those platforms (unless I'm in out in some company office). I don't dual-boot Ubuntu with Windows or Mac. I use the Ubuntu-MATE distro.

I'll eventually set up dual-boot of Ubuntu-MATE 20.04 LTS and Ubuntu-MATE 22.04 LTS (see below). Those Ubuntu-MATE OSs will be on separate, internal SSD drives.

2a. Is it enough to get a live (live-only) USB boot drive, that can boot in UEFI mode (and run live sessions and install Ubuntu)?

My goal is to get a live USB boot drive working for the purpose of installing a UEFI/GPT Ubuntu-MATE 20.04.1 onto an external, standalone one-terabyte SSD. That SSD will have one big partition (root and /home) and a bit of free space at the beginning and end. Very simple.

This external drive will then replace my current internal 18.04 Ubuntu-MATE install. (And I'll then put the 18.04 drive in an external enclosure.)

Because of the bug where UEFI apparently installs boot files on the first drive it sees, I plan to physically unplug both of my current two internal SSDs when I do this UEFI/GPT install.

The install will go directly from the plugged-in live-boot USB flash drive to the connected external SSD drive, with no internal drives present in the chain to muck up the install.

Much, much later I will have a separate (one-TB) internal SSD with Ubuntu 22.04 installed on it. Then, both my internal 20.04 drive and the future 22.04 internal drive will both be UEFI/GPT. This is the plan for going forward that I'm trying to get started now.

2b. Or do you need a live system, that can store data past shutdown/reboot, a persistent live drive?

Yes, as stated above.

2c. Or do you want an installed system (like installed in an internal drive, but in a USB drive)?

Ultimately it will be an installed system on an internal SSD drive (it's just that that drive is, at the moment, external). The USB drive is only for the purpose of putting a working UEFI/GPT 20.04.1 onto an external SSD drive that will soon be moved to inside my desktop workstation box.

3a. Is it enough, that the drive can boot in UEFI mode?

Yes. What I want is a working system that is a UEFI/GPT Ubuntu-MATE 20.04, on an SSD that will ultimately be internal and will be my working system.

3b. Or should it boot also in BIOS mode (alias CSM alias legacy mode)?

No. I want to move away from BIOS to UEFI. If I discover for any reason that the install absolutely must be BIOS as well, I suppose I would then want it to be -- if possible -- bootable via BIOS as well as UEFI. But I don't think that'll be the case, and I'd like to avoid that. My machine does have the capacity to boot via UEFI.

This [error message] output can be printed but the live session will work anyway. You need not worry too much about it (in a live session).

Well, I get the willies when I see error messages like that. The USB drive does boot into the trial 20.04, though. I'll probably give it a try.


I do have a question about the SSD drive I want to install to: Is my current formatting of it correct or workable?

Right now I have that (empty) SSD formatted like this:

(a) its partition table is set as GPT;
(b) it has a 200 MB allocated empty space at its beginning;
(c) its first partition is a fat32, one-GB to be used as the ESP;
(d) its second partition is the large (893 GB) partition where root and home will go;
(e) it has a small (2 MB) unallocated empty space at its end.

Is this the way I can have the SSD drive set up ahead of running an installer on it, to create a UEFI/GPT SSD drive? Will the installer put the boot files on what I have set up as the fat32 ESP drive?

Or should I delete all this and be creating the partitions as part of the install process? I've already tried this install once with a previous 4-GB live boot USB key, instructing in the process NOT to wipe the drive, but UEFI did not appear in the partition-setup pop-up "use as" menu.

(I think that previous key was set up to be a BIOS boot, and thus didn't work for UEFI.)

[dragonfly41]

My goal is to get a live USB boot drive working for the purpose of installing a UEFI/GPT Ubuntu-MATE 20.04.1 onto an external, standalone one-terabyte SSD. That SSD will have one big partition & a bit of free space at the beginning and end. Very simple.

I would just add that I would place an ESP Fat32 partition (500mbytes) before your Ext4 partition.
You can then use this to boot your SSD on its own when needed.
I have two external SSD's so configured (switched using rEFInd)..

[watchpocket]

Thanks. See what I just now added to the end of my post directly above. I have the SSD (that I want to install to) formatted that way now, but I need to make sure the install will go correctly. I've been looking at rEIFInd also, I'll likely try to use it as well.

[oldfred]

Its Ubuntu's Ubiquity that will not let you choose where to install grub2's UEFI boot files.
You can do a work around, or reinstall grub after your install. Default will install /EFI/ubuntu into first drive seen. If you disconnect all other drives, either logically in UEFI or physically then it will install to your external drive.

Posted work around to manually unmount & mount correct ESP during install #23 & #26
https://bugs.launchpad.net/ubuntu/+s...y/+bug/1396379
Others suggest disconnecting all other drives physically or logically in UEFI settings, so install drive is first drive.
Or removing boot flag/esp flag from first drive, so only ESP is in the install drive. (I have not had that work, but others have.)
Or if you have ESP on second or external drive, you can just reinstall grub, either manually or using Boot-Repair's advanced mode & full reinstall to correct drive.