Arch Linux

riverpunk

Member

Registered: 2025-03-03

Posts: 2

Creating an EPHEMERAL Arch Installation on a Live USB?

I've seen that the wiki has a good amount of information regarding how to install Arch Linux to a portable USB or other medium, including information on how to improve the lifespan of the medium by avoiding unnecessary writes to the disk (https://wiki.archlinux.org/title/Instal … ble_medium).

This method of course is more for if you want to actually have a persistent system, which is also portable. What I'm trying to do is to create an ephemeral medium which would work a lot like the Arch Installation Medium, except that I would like to be able to configure it a bit towards my needs. For instance, I would like to include certain extra packages (such as a DE) in the system by default, and also possibly configure how much RAM gets allocated to virtual disk space.

What I kind of want out of this is something somewhat similar to Tails OS, except without such a focus on extreme privacy -- I don't need all my internet going through the Tor Network, for instance. I don't really have any specific reason I'm trying to make this except for the sake of understanding computers on a deeper level.

In my mind, there's two ways I can approach this problem:

1) Follow the directions described in https://wiki.archlinux.org/title/Instal … ble_medium (previously linked above), and then find a way to prevent all write operations from being sent back downstream to my live medium.

or

2) Create my own modified variant of the Arch Linux Installation Medium, with my own added packages depending on what I want to be available each boot, and possibly modified parameters for how much RAM to allocate for virtual disk space. I'm out of my depth in terms of deciding how difficult this might be, it's possible I could open an entire can of worms by making even slight modifications to this.

I'm wondering if any of you guys might know anything about how I might accomplish this? When I was reading the main section of USB flash installation medium, it seems to be indicating that the ephemeral property of the medium has something to do with overlayfs, but I feel a bit over my depth in terms of understanding how exactly to use it for my use-case.

mpan

Member

Registered: 2012-08-01

Posts: 1,376

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Re: Creating an EPHEMERAL Arch Installation on a Live USB?

If you want to have it all stored in RAM, perhaps building your custom archiso is what you want? Remember that booting from a USB stick is going to be slow, in particular given you’re unpacking the entire system image to RAM.

If you need it to be secure against malware, make sure you use a USB stick with reputable hardware write protection. Dunno what is good nowadays. In the past Kanguru⁽¹⁾ SS3 and FlashBlu had good opinions.

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⁽¹⁾ They also have many encrypted and certified hardware: this isn’t needed in this case. Don’t get confused.

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Sometimes I seem a bit harsh — don’t get offended too easily!

riverpunk

Member

Registered: 2025-03-03

Posts: 2

Re: Creating an EPHEMERAL Arch Installation on a Live USB?

If you want to have it all stored in RAM, perhaps building your custom archiso is what you want? Remember that booting from a USB stick is going to be slow, in particular given you’re unpacking the entire system image to RAM.

This is exactly what I was looking for thank you! I was worried I would have to manually tweak the official release. It seems that this is the tool they actually use to build the official release in the first place, so using this would be better. For anyone else in my same boat reading this, I also see it's got information regarding how to change the size of the virtual disk under https://wiki.archlinux.org/title/Archis … ile_system, both on your custom build, but also how to adjust it at boot time by pressing `e` or `tab`, or even after boot time by using a command.

I will definitely have to play around with this and see what kind of options are feasible for a portable system I'm trying to put together.

kermit63

Member

Registered: 2018-07-04

Posts: 306

Re: Creating an EPHEMERAL Arch Installation on a Live USB?

While you're learning archiso, a cheesy stop-gap solution is to use the live iso of one of those arch-based distros. Aside from manjaro, most of these distros uses arch's repo and is close enough to arch that you can use it as a rescue usb for your arch installation.

Most of them packs a whole lot of installed packages already so that it feels like some sort of immutable installed system on the usb. Which distro to choose depends on your use-case vis-a-vis installed packages. They are quite big though, probably in the range of 4GB.

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eznix

Member

Registered: 2020-06-29

Posts: 28

Re: Creating an EPHEMERAL Arch Installation on a Live USB?

While you're learning archiso, a cheesy stop-gap solution is to use the live iso of one of those arch-based distros. Aside from manjaro, most of these distros uses arch's repo and is close enough to arch that you can use it as a rescue usb for your arch installation.

Most of them packs a whole lot of installed packages already so that it feels like some sort of immutable installed system on the usb. Which distro to choose depends on your use-case vis-a-vis installed packages. They are quite big though, probably in the range of 4GB.

It's not a cheesy, stop-gap solution. It is useful to glean solutions and approaches from others while learning the ropes in creating your own ISO. I used this method when creating my own Arch based systems five years ago and I am still going strong with my Ezarcher project.

Last edited by eznix (Yesterday 19:00:42)