grub 2:2.14-1 cant boot iso image from hard drive via grub

pure71453 · 2026-04-20 11:39:08

I am tried to boot iso image from hard drive via grub but got error: disk /loopback.c: delete_loopback:67: device not found. Prev i just downgrade grub package and all works. But now i dont remember what old package version was working. How to fix it without downgrading grub package?

pure71453 · Yesterday 03:38:43

Same issue on eos, debian-testing

seth · Yesterday 06:03:33

Prev i just downgrade grub package and all works. But now i dont remember what old package version was working.

/var/log/pacman.log knows

If the downgrade helps, please record the functional version. Otherwise

I am tried to boot iso image from hard drive via grub

please post your grub.cfg

pure71453 · Yesterday 10:54:13

seth wrote:

Prev i just downgrade grub package and all works. But now i dont remember what old package version was working.
/var/log/pacman.log knows
If the downgrade helps, please record the functional version. Otherwise
I am tried to boot iso image from hard drive via grub
please post your grub.cfg

Can you boot any iso image from grub with loopback from hard drive?

GerBra · Yesterday 13:01:15

grub 2:2.14-1

Infos: Myself use btrfs AND my /boot folder is on the btrfs root device. My small ESP contains only the grub efi binary.
So my path entries contain /@/path_to.
Modify for your setup.
My iso images are in /boot-isos on btrfs root, so you may have to modify your paths according your setup
I try according like https://wiki.archlinux.org/title/Multib … ot_entries

I boot 2 iso images:
a) grml
https://download.grml.org/grml-full-2025.12-amd64.iso
/boot/grub/grub.cfg

menuentry "Grml Rescue System (grml-full 2025.12)" {
        insmod part_gpt
        insmod btrfs
        iso_path="/@/boot-isos/grml-full-2025.12-amd64.iso"
        export iso_path
        search --no-floppy --set root --file "$iso_path"
        kernelopts=" ssh=password toram  "
        export kernelopts
        loopback loop "$iso_path"
        set root=(loop)
        configfile /boot/grub/loopback.cfg
}

This boots perfectly and is usable

b) Archlinux install iso

menuentry '[loopback]archlinux-2026.03.01-x86_64.iso' {
    insmod part_gpt
    insmod btrfs
    set iso_path='/@/boot-isos/archlinux-2026.03.01-x86_64.iso'
    export iso_path
    search --set=root --file "$iso_path"
    loopback loop "$iso_path"
    set root=(loop)
    configfile /boot/grub/loopback.cfg
    #loopback --delete loop
}

This iso image boots perfectly (I see the uefi grub(?) menu) and could use ex. the memtest86
But: if i select to boot the archlinux setup entry it starts but break, see this picture:
https://paste.c-net.org/FlushLeukemia
But it seems (in an "own" hook ?) to setup another loopback device instead using the provided from main grub???
I work on this, the /boot/grub/loopback.cfg on the iso looks IMHO ok... Currently not my main project, i have not looked further now.

But you may get a inspiration...

Last edited by GerBra (Yesterday 13:39:57)

pure71453 · Today 01:34:12

GerBra wrote:

grub 2:2.14-1
Infos: Myself use btrfs AND my /boot folder is on the btrfs root device. My small ESP contains only the grub efi binary.
So my path entries contain /@/path_to.
Modify for your setup.
My iso images are in /boot-isos on btrfs root, so you may have to modify your paths according your setup
I try according like https://wiki.archlinux.org/title/Multib … ot_entries
I boot 2 iso images:
a) grml
https://download.grml.org/grml-full-2025.12-amd64.iso
/boot/grub/grub.cfg
menuentry "Grml Rescue System (grml-full 2025.12)" {
        insmod part_gpt
        insmod btrfs
        iso_path="/@/boot-isos/grml-full-2025.12-amd64.iso"
        export iso_path
        search --no-floppy --set root --file "$iso_path"
        kernelopts=" ssh=password toram  "
        export kernelopts
        loopback loop "$iso_path"
        set root=(loop)
        configfile /boot/grub/loopback.cfg
}
This boots perfectly and is usable
b) Archlinux install iso
menuentry '[loopback]archlinux-2026.03.01-x86_64.iso' {
    insmod part_gpt
    insmod btrfs
    set iso_path='/@/boot-isos/archlinux-2026.03.01-x86_64.iso'
    export iso_path
    search --set=root --file "$iso_path"
    loopback loop "$iso_path"
    set root=(loop)
    configfile /boot/grub/loopback.cfg
    #loopback --delete loop
}
This iso image boots perfectly (I see the uefi grub(?) menu) and could use ex. the memtest86
But: if i select to boot the archlinux setup entry it starts but break, see this picture:
https://paste.c-net.org/FlushLeukemia
But it seems (in an "own" hook ?) to setup another loopback device instead using the provided from main grub???
I work on this, the /boot/grub/loopback.cfg on the iso looks IMHO ok... Currently not my main project, i have not looked further now.
But you may get a inspiration...

downgrading package grub (2:2.14-1 => 2:2.12.r292.g73d1c959-1)
Iso images are located on separate ssd with ext4. Now i can boot any iso image via grub from hard drive with loopback.cfg
for linux mint:
menuentry "linuxmint" {
iso_path="/linux/linuxmint23/linuxmint-22.3-xfce-64bit.iso"
export iso_path
search --set=root --file $iso_path
loopback loop $iso_path
root=(loop)
configfile /boot/grub/grub.cfg
loopback --delete loop
}

pure71453 · Today 01:39:02

When maintainers will fix it?

cryptearth · Today 03:48:05

when someone has reported a proper issue: https://gitlab.freedesktop.org/gnu-grub … work_items

seth · Today 07:40:17

Iso images are located on separate ssd with ext4.

Does booting images (eg. tinycore will likely not be a problem itr) from the boot partition work and does it help to explicitly insmod part_gpt/ext4?
Is the separate disk SATA or USB?

Then that's not your grub.cfg but some random snippet and on a formal note, please use [code][/code] tags and avoid bloating the thread with mindless full-quotes of previous posts.

GerBra · Today 10:21:32

FTR.

This menuentry now boots also perfectly the current archlinux iso:

menuentry '[loopback]archlinux-2026.03.01-x86_64.iso' {
    insmod part_gpt
    insmod btrfs
    set iso_path='/@/boot-isos/archlinux-2026.03.01-x86_64.iso'
    export iso_path
    search --set=root --file "$iso_path"
    probe -u --set=archiso_img_dev_uuid $root
    export archiso_img_dev_uuid
    loopback loop "$iso_path"
    set root=(loop)
    configfile /boot/grub/loopback.cfg
}

Now i could not even boot the iso from system-grub, i also could start (via iso-grub) the archlinux iso (install) system.
The (iso) grub boot entry expects two variables:
iso_path : path to the archlinux.iso
archiso_img_dev_uuid : the UUID of the device where $iso_path gets found.
With these exported values the (iso)grub boot entry will generate the correct linux <options> line, the (iso) hooks then setup their own loopback.

This differs a bit from mentioned wiki page https://wiki.archlinux.org/title/Multib … ot_entries
Maybe because the archiso releng structure are now different?

And: All my mentioned iso boots works with current grub package 2:2.14-1. I don't have to downgrade something.

//Edit: @pure71453
You say you have to downgrade grub package. Have you checked what version is currently installed as your grub bootloader (on the device!). Look at the top version string of your bootloader. Maybe the installed one is too old (not compatible ?) with the current grub package version...

Last edited by GerBra (Today 10:48:46)

Arch Linux

#1 2026-04-20 11:39:08

grub 2:2.14-1 cant boot iso image from hard drive via grub

#2 Yesterday 03:38:43

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#3 Yesterday 06:03:33

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#4 Yesterday 10:54:13

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#5 Yesterday 13:01:15

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#6 Today 01:34:12

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#7 Today 01:39:02

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#8 Today 03:48:05

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#9 Today 07:40:17

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

#10 Today 10:21:32

Re: grub 2:2.14-1 cant boot iso image from hard drive via grub

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