6MB (kernel) + 3.5MB (initrd) = 9.5MB .
If you need the in 10MB, create a custom initrd as shown above. If you need a functional OS of that size, switch your search to "TinyCore" or "Bootable Ubuntu kernel only" . ubuntu highly compressed 10mb
This boots into a root shell where you can run apt (if you add network modules). It’s not a full Ubuntu, but it’s Ubuntu-compatible at the kernel level. Ubuntu Core is a snap-only version of Ubuntu for IoT. A compressed image of the minimal "gadget" snap can be as low as 15-20MB – tantalizingly close. However, it expands to ~200MB on installation. 6MB (kernel) + 3
Or, accept that is a myth propagated by clickbait YouTube videos showing fake dd commands. The real achievement is a 50MB Ubuntu rescue disk – which, in 2025, is still incredibly impressive. Final Recommendation | Use Case | Best Solution | Size | |----------|---------------|------| | True 10MB Linux | TinyCore Linux (non-Ubuntu) | 10-16 MB | | Ubuntu-like rescue | Custom BusyBox + Ubuntu kernel | 9-12 MB | | Minimal apt-capable OS | Debian Netinstall (aggressively compressed) | 30-45 MB | | Portable Ubuntu env | Ubuntu Core on a USB (SquashFS compressed) | 60 MB | This boots into a root shell where you
mksquashfs ubuntu_root/ ubuntu.squashfs -comp xz -Xdict-size 1M -b 1M The Ultimate Packer for Executables (UPX) can shrink individual binaries by 50-70%.
sudo apt install upx-ucl find ubuntu_root/usr/bin -type f -executable -exec upx --ultra-brute {} \; A standard bash binary (1.1MB) compresses to 380KB with UPX. Across 50 core binaries, you save ~40MB. Real-World Project: Ubuntu "Micro" – A 10MB Torrent Client Let’s apply all this to a practical project: A 10MB Ubuntu environment that can run BitTorrent .
# Install required tools on Ubuntu sudo apt install build-essential libncurses-dev busbox-static git clone https://github.com/tinycore/linux-kernel-config make tinyconfig # Enable only essential drivers Build kernel make -j$(nproc) Result: bzImage ~ 6MB Create initrd with BusyBox mkdir initrd cd initrd cp /bin/busybox ./bin/ ln -s busybox ./bin/sh echo '#!/bin/sh' > init echo 'mount -t proc none /proc' >> init echo 'exec /bin/sh' >> init chmod +x init find . | cpio -o -H newc | xz --extreme > ../initrd.xz Result: initrd.xz ~ 3.5MB