How much space do I need for a bootable usb drive?

Let’s say If I have a usb drive of 8 gb and I create two partition one of 5 gb and second partition of rest gb (technically it’s not 8 gb) . On 5 gb I create a bootable partion of manjaro , so would that be enough?

I doubt it. It might work for storing an ISO — disclaimer: I haven’t checked the size — because that’s a compressed filesystem and it will be decompressed in RAM when run, but for a working installation, I seriously doubt it.

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If you are talking about real installation (if you are talking about installation media live usb you see that the .iso is about 3GB and that is what you need), the answer is probably not. You can certainly squeeze a minimal install there. And disable or make very small swap (like 2-300mb if you have enough ram). And tell the journal to write to volatile only. BUT: the problem comes when you have to update. This is a rolling release. The todays stable update was 1.7 GB on my machine. OK, i have a lot of apps. But even on a minimal install an update can be 500MB. And you do not want to run out of space when updating.
AND keep in mind ext filesystems do not like to be very full. So from the 5 GB you will have to keep about a gig free or the system will be awfully slow because of defragmentation, even if you have a lot of ram. I have been there…
So if you have a 5GB partition, you will actually want to ensure that your system stays below 3-3,5 GB.
Besides, flash drives are slow and many tend to overheat with such usage.
If you really need a system on the go, either use a bigger flash, or Tails, or Debian.
To sum up: It should be doable with some effort, but would not be fun.


It was about 5.6 GiB on my machine after unpacking, but I too run a fairly elaborate system here.

My /usr is currently 11 GiB, and that’s on btrfs with zstd compression… :wink:

Correction: the download size was 1.7GB. I didn’t check how much was it after unpacking.

So that means he has to go below 3 Gb for the install…that means the next thing that has to go is the DE. A window manager at most for that size. Openbox or similar.


I think I wasn’t clear enough what I meant by partition ! I wasn’t talking about hard drive partition I was talking about usb partition so on one partition I have bootable manjaro and on another partition I just use it for storing files. And yes indeed iso is around 3.2 gb so how much space I need for bootable manjaro in USB

This question you can easily answer yourself by trying. :stuck_out_tongue_winking_eye:

So you actually want an ordinary installation media. Well, then the iso size and a couple of megs for boot files maybe. The real trick will be to choose the tool to create the drive, many work with whole drives and not with partitions, but that is additional reading for you (worst case: you will have to use DD from the terminal to write the image). I know it is possible, but have not done it myself (except with ventoy, but i am not sure if doing an installation media with ventoy will be ok or lead to problems)

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I always use DD actually I only used Rufus when I was on windows and that was long time ago , so I guess I only need 1 more gb so I think I should give it a try (if only couple of more megs require after 3.2 gb)

Note that you may lose your installation during the first update :wink:

He doesn’t want to install, i misunderstood the first post too.

I was trying to do the same.

So what is the minimum space we should allocate to a partition in the USB to create a live bootable USB? I’ll only use this for occasional installation or troubleshooting of other PCs.

(considering the iso file is 4GB, will 10GB be good enough?)

Use Ventoy.
Put an ISO on it - or two …
Boot from it when you need to.

Use the capacity of your USB drive for actual storage.

It appears that you don’t need an installed system - just one that you can use when you need to.
A simple boot of a live system seems to fit the bill.


Wow, that’s a great find. Didn’t know about ventoy.
Thank you very much