Can't boot from eoan-desktop-amd64.iso

[kagashe]

I downloaded the iso from http://cdimage.ubuntu.com/daily-live/current/
and tried to boot from grub:

menuentry "Eoan Desktop iso" {
            set isofile="~/eoan-desktop-amd64.iso"
            loopback loop (hd0,X)$isofile
            linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile noprompt noeject
            initrd (loop)/casper/initrd
    }

but got this error

/scripts/casper-premount/20isoscan: line 59: try_mount: not found

There is a Bug reported on launchpad by a user on 2019-08-26 in this regard.

But I thought I should report here since the Bug is not replied.

Kamalakar

[guiverc]

That bug has not been reported in eoan ISO testing (http://iso.qa.ubuntu.com/qatracker/reports/bugs/1841455) which could provide a greater chance of being noticed.

The bug also didn't have any 'tags' (eoan & iso-testing have now been added), but since the bug impacts you, I'd suggest downloading the latest ISO & recording a test on http://iso.qa.ubuntu.com/qatracker/m...nes/404/builds so it appears in eoan ISO testing reports.

[kagashe]

I'd suggest downloading the latest ISO & recording a test on http://iso.qa.ubuntu.com/qatracker/m...nes/404/builds so it appears in eoan ISO testing reports.

I am not sure whether booting from iso is a recognised method for iso testing or not. I prefer booting directly from iso since I could update it through zsync and boot the updated version.

I made a Startup disk from the iso on my existing Ubuntu 18.04 installed system and I could boot into current live Ubuntu 19.10 from the USB, however, the fact remains that I could not boot directly from iso.

Kamalakar

[guiverc]

To me the testcase would be 'live session' and I would expect it to be a standard 'try ubuntu'; as the difference as I saw it, was you're just not booting from the usual cd/dvd/thumb-drive, and you can note this in the comments.

The wording does differ for the various flavors (eg. Lubuntu's live says only to "Boot up the image") which is what you'd be doing, but if the testcase for your flavor doesn't match, don't do it - or make it clear what you're doing in the comments. If you have problems - then it's a normal launchpad bug report which will be linked to the QA-test once you enter the bug report number (this to me is the point; it allows easy date & frequency automatic bug tracking)

[sudodus]

@kagashe,

Your problem with booting from grub and that bug report made me check if mkusb can create a live drive with the current daily iso file of Ubuntu Eoan.

The reason is that mkusb uses grub to boot both in BIOS mode and UEFI mode when creating a persistent live drive.

I ran mkusb-dus in an installed Ubuntu system with 18.04.x

dus eoan-desktop-amd64.iso

The result, a persistent live drive with Ubuntu Eoan works as it should.

So maybe something is wrong with your menuentry. I am guessing here: Are you sure that grub can resolve the tilde character ~? Have you pointed to other (older) iso files that way and it has worked?

---

Edit: After thinking a while, I would like to ask: Where do we think that the bug is located: In the grub that is running or in the iso file?

Also, mkusb is not booting via grub into an iso file, but into a cloned image of an iso file (residing in partition #4). So there is a difference.

[kagashe]

@kagashe,
So maybe something is wrong with your menuentry. I am guessing here: Are you sure that grub can resolve the tilde character ~? Have you pointed to other (older) iso files that way and it has worked?.

The tilde character is not there in the actual path (/home/user/eoan-desktop-amd64.iso) I have indicated it here to show that the iso is placed in the home folder of sdaX. I am using this method to test all Ubuntu Development versions so far. In fact the menuentry for disco-desktop-amd64.iso still exist and I can boot it.

---

Edit: After thinking a while, I would like to ask: Where do we think that the bug is located: In the grub that is running or in the iso file?

There is a hint about the location of the bug by John Little in the reply on Launchpad Bug which is reproduced below:

I was trying the Kubuntu eoan daily build. I had a look in the squashfs. In the initramfs-tools/scripts/casper-premount/20iso_scan script, it invokes the find_path function, which is defined in scripts/lupin-helpers. It's line 59 of that script that has the try_mount invocation. In my disco iso the try_mount function is defined in scripts/casper-helpers, but the eoan version does not.

Kamalakar

[sudodus]

Thanks Kamalakar,

I have been testing too, with grub booting into the iso files

/lubuntu-18.04.1-desktop-amd64.iso
/ubuntu-eoan-desktop-amd64.iso

and I have identified the initrd files in the iso files, so with /etc/grub.d/40_custom

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry "Eoan Desktop iso" {
            set isofile="/ubuntu-eoan-desktop-amd64.iso"
            loopback loop (hd0,1)$isofile
            linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile noprompt noeject
            initrd (loop)/casper/initrd
}
menuentry "Lubuntu 18.04.1 Desktop iso" {
            set isofile="/lubuntu-18.04.1-desktop-amd64.iso"
            loopback loop (hd0,1)$isofile
            linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile noprompt noeject
            initrd (loop)/casper/initrd.lz
}

Booting from grub (into an iso file) works with the 18.04.1 iso file, but not with the Eoan iso file where I get the same error output as you. In other words, you are right, and I will click 'affects me too' in the bug report.

/Nio

[kagashe]

SOLVED after zsync iso to version 2019-10-01 15:12

Kamalakar

[sudodus]

Yes, now grub-n-iso works for me too, tested with the lubuntu eoan iso file dated Oct 3