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#1 2025-10-21 20:24:31

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

[SOLVED] How do i create a working bootable usb from arch?

Hi guys,

---------------------------------------------------------------------------------------
SOLUTION:
fdisk -l to find the right drive, i will use /dev/sdX as example.

dd if=/path/to/iso of=/dev/sdX
sync
fdisk /dev/sdX

press a to set the bootable flag
press 2 and enter to set partition 2 bootable
press w and enter to write to disk
Now reboot and it works
---------------------------------------------------------------------------------------

I have been trying to get a usb flashdrive to turn into a bootable Arch installer from within Arch + Plasma to install Arch for my niece.
For some reason i have no clue how to get my flashdrive to become bootable.

This is what i already tried:

I checked, double checked and tripple checked that /dev/sda is my usb stick, this used to be my main hdd in the past so it still feels weird but whatever.
To start i used

fdisk /dev/sda

press d to remove all the partitions, add a single partition with n, p for primary and write to disk with w.
Then i formatted it with:

mkfs.fat -F 32 /dev/sda1

I did these both after every failed attempt.

After this i used dd to write the image to the disk like so:

dd if=/home/blabla/Downloads/archblabla.iso of=/dev/sda status=progress

When i mount the flashdrive it seems normal to me, files seem to be there.
Reboot machine, keep pressing esc to open uefi boot menu, and guess what? nothing there but my beloved grub.
Normally i am happy to see this but not today >.<

So i thought maybe i just better use a gui and tried at least these, maybe more:

1. BalenaEtcher > same happens
2. gnome-image-writer > same happens
3. Fedora media writer > same happens
4. ISO Image Writer > same happens
5. Impression > same happens

At this point i got sick of rebooting and started to doubt the iso file so i installed virtualbox only to realize i cant boot from usb with it and got utterly annoyed,
I did however test the iso file with virtualbox and that just boots up, no issues.

What the hell am i doing wrong??? How the hell do i make a bootable USB from within linux?? Im confused.
I have been using linux for ages and never ever before did i need to do this since i always used my windows pc for this.
Which is now finally a arch pc since win10 is EOL so for the first time since Debian Potato i need to make a bootable usb from within linux and i just cant do it LOL >.<
I feel like a total noob please help.

Last edited by chillecharlie (2025-10-21 23:09:27)

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#2 2025-10-21 21:17:16

cryptearth
Member
Registered: 2024-02-03
Posts: 2,094

Re: [SOLVED] How do i create a working bootable usb from arch?

when you overwrite the thumbdrive wth an image you can skip the fdisk as all it does gets overwritten anyways
where you got the iso from? what version?
the standard archiso is capable to boot both on legacy and uefi - and so should a thumbdrive when you just flash an iso onto it
not able to boot from it sounds more like a system issue than the image

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#3 2025-10-21 21:25:50

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

Re: [SOLVED] How do i create a working bootable usb from arch?

I got the iso from

https://archlinux.mirror.liteserver.nl/iso/2025.10.01/archlinux-2025.10.01-x86_64.iso

I think i may have found the issue, just not the solution yet.
When i do fdisk -l after dding the image to the usb drive i notice something weird:

Disk /dev/sda: 29.22 GiB, 31376707072 bytes, 61282631 sectors
Disk model: Extreme         
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x5f1a4092

Device     Boot   Start     End Sectors  Size Id Type
/dev/sda1  *         64 2457599 2457536  1.2G  0 Empty
/dev/sda2       2457600 2967551  509952  249M ef EFI (FAT-12/16/32)

Also if i mount the partitions this is whats on it:

➜  ~ sudo mount /dev/sda1 /mnt/usb
mount: /mnt/usb: WARNING: source write-protected, mounted read-only.
➜  ~ ls /dev/usb
hiddev0  hiddev1  hiddev2  hiddev3  hiddev4
➜  ~ sudo umount /mnt/usb
➜  ~ sudo mount /dev/sda2 /mnt/usb
➜  ~ ls /mnt/usb 
arch  boot  EFI  loader  shellia32.efi  shellx64.efi
➜  ~ 

Should that first partition even be there at all?

Last edited by chillecharlie (2025-10-21 21:26:11)

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#4 2025-10-21 21:28:50

cryptearth
Member
Registered: 2024-02-03
Posts: 2,094

Re: [SOLVED] How do i create a working bootable usb from arch?

first: you mistyped ls /dev//usb instead of /mnt
but: its intented to be there as thats the legacy iso9660 partition (hence read-only)

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#5 2025-10-21 21:32:19

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

Re: [SOLVED] How do i create a working bootable usb from arch?

I figured it out, i was right that first partition should not be there.
I removed it like this:

fdisk /dev/sda

pressed D for delete
pressed 1 for first partition
pressed W for write to disk
reboot now > bootable disk is in uefi menu and seems to boot into rootfs.

However now i only have a rootfs shell, which i still cant use to install arch with.

Last edited by chillecharlie (2025-10-21 21:59:11)

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#6 2025-10-21 21:36:20

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

Re: [SOLVED] How do i create a working bootable usb from arch?

cryptearth wrote:

first: you mistyped ls /dev//usb instead of /mnt
but: its intented to be there as thats the legacy iso9660 partition (hence read-only)

Ah yes oopsie, thats right! let me make another.

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#7 2025-10-21 21:40:19

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

Re: [SOLVED] How do i create a working bootable usb from arch?

➜  ~ sudo mount /dev/sda1 /mnt/usb
mount: /mnt/usb: WARNING: source write-protected, mounted read-only.
➜  ~ ls /mnt/usb
arch  boot  EFI  loader  shellia32.efi  shellx64.efi
➜  ~ sudo mkdir /mnt/usb2
➜  ~ sudo mount /dev/sda2 /mnt/usb2
➜  ~ ls /mnt/usb2
arch  boot  EFI  loader  shellia32.efi  shellx64.efi
➜  ~

I figured id try this usb now on my old laptop just to see if i can install arch from this shell.
I can not.
it is a rootfs shell so i can not even use fdisk with it.

Last edited by chillecharlie (2025-10-21 21:56:37)

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#8 2025-10-21 22:34:45

cryptearth
Member
Registered: 2024-02-03
Posts: 2,094

Re: [SOLVED] How do i create a working bootable usb from arch?

as said: BOTH partitions are supposed to be there
the bigger one contains the archinstall root fs ramdisk - without it you're left only with an ESP - an efi system partition with an efi capable boot loader
the disc image is done in a specific way to support both old legacy systems and new uefi systems - tinkering and just removing partiitons without understanding any of it won't get you far
I recommend give ventoy a shot - it will prepare a proper boot thumbdrive with an exfat partition you just have to put the iso into - the boot loader will do the magic for you

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#9 2025-10-21 22:46:46

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

Re: [SOLVED] How do i create a working bootable usb from arch?

Ventoy has given me nothing but headaches honestly, lots of hardware just wont work with it.
Lots of isos just wont work with it either.
Im clueless whats going wrong with just dd to the usb drive, what am i missing here?

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#10 2025-10-21 23:00:28

chillecharlie
Member
Registered: 2025-10-02
Posts: 11

Re: [SOLVED] How do i create a working bootable usb from arch?

Found it.
dd doesnt seem to copy the bootable flag.

Solution is simple.

fdisk -l to find the right drive, i will use /dev/sdX as example.

dd if=/path/to/iso of=/dev/sdX
sync
fdisk /dev/sdX

press a to set the bootable flag
press 2 and enter to set partition 2 bootable
press w and enter to write to disk
Now reboot and it works

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#11 2025-10-22 10:04:36

cryptearth
Member
Registered: 2024-02-03
Posts: 2,094

Re: [SOLVED] How do i create a working bootable usb from arch?

both your complain about ventoy as well as your solution about setting a bootable flag raises so many red flags and questions - but for the sake to not escalate this let me just silently congratulate upon you seem to found something that works for you (although the likely reason why it work would fill its own topic)

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