A 3 MB boot ISO that installs 19 server operating systems, unattended.
Rack the server, attach the image to iDRAC, iLO or any IPMI virtual media console, answer five prompts, pick an OS, walk away. It reboots into a configured system with SSH root login. No PXE server, no DHCP, no account — we build and publish it free, from the team behind the FluxBilling hosting billing, DCIM and IPAM platform.
v1.0 · ~3 MB · BIOS + UEFI · 19 OS entries · GPL-2.0-or-later
The FluxBilling OS Installer is a free, open-source boot image of roughly 3 MB that installs nineteen server operating system entries — Ubuntu, Debian, AlmaLinux, Rocky Linux, CentOS Stream and openSUSE Leap — without a PXE server, a DHCP scope or a management host. Every heavy payload streams at boot from the official distribution mirrors over the data NIC you choose in the menu, so the slow management port only ever carries the 3 MB image. You type the network configuration, hostname and root password once at the console; the matching answer file — cloud-init, preseed, kickstart, AutoYaST or Agama — is generated on the machine and injected into the vendor initrd in memory. It is released under GPL-2.0-or-later, requires no account, and is unrelated to any FluxBilling subscription.
Five prompts, then it is out of your hands.
The NIC list is live, so you pick the port that is actually cabled rather than guessing a kernel name. Address and prefix are one field, the gateway is calculated for you, and the password field is hidden. A review screen follows — every value can be corrected before anything is written to disk.
The first entry in the OS menu toggles between AUTOMATED — answer files injected, zero-touch, watchable over serial — and MANUAL, which boots the same installer with no answer file for a hand-driven install.
Port number [ENTER = 0] # live NIC list
IP / subnet: 203.0.113.111/27 # /1../31
Gateway [ENTER = 203.0.113.97] # calculated
Hostname: node07.rack12
Password: •••••••••• # hidden
--- review, fix any field, then pick an OS ---
[AUTOMATED] Ubuntu 24.04 LTS
[AUTOMATED] Debian 13
[AUTOMATED] AlmaLinux 9
Everything heavy is fetched at boot, over the NIC you choose.
Kernels, initrds and install images stream straight from the vendors’ mirrors across the data interface. The management port — the slow one — only ever carries three megabytes.
Tiny
~3 MB. It attaches over IPMI virtual media in seconds instead of streaming a 3 GB image down a management port.
Zero-touch
Hostname, static IP and root password are typed once, at the console. The install runs unattended from there.
No PXE, no DHCP
Static addressing straight from the boot menu. Nothing to stand up in a colocation rack you do not control.
Manual mode
One toggle boots the same installer interactively, with no answer file, when a box needs hand-holding.
BIOS and UEFI
Serial console (SOL) mirrored throughout, and /31 point-to-point subnets are handled like any other prefix.
Nothing phones home
No private config webserver: installer identity and network config are generated on the machine itself.
Nineteen entries, each driven by its own native answer file.
No generic wrapper pretending every distribution installs the same way. Each family is automated the way its own installer expects.
| Family | Versions | Automated with |
|---|---|---|
| Ubuntu | 26.04 LTS, 25.10, 24.04 LTS, 22.04 LTS | Cloud-init seed generated at boot |
| Ubuntu (legacy installer) | 20.04, 18.04 | Preseed + kernel cmdline |
| Debian | 13, 12, 11 | Preseed + kernel cmdline |
| AlmaLinux | 10, 9, 8 | Kickstart (%pre from cmdline) |
| Rocky Linux | 10, 9, 8 | Kickstart |
| CentOS Stream | 10, 9 | Kickstart |
| openSUSE Leap | 15.6 | AutoYaST profile |
| openSUSE Leap | 16.0 | Agama profile injected into the initrd |
Rack it, attach it, answer five prompts, walk away.
Four steps from a bare machine to a system you can SSH into. Nothing is staged on a server you have to run first.
- 01
Attach the image
Mount the 3 MB ISO through iDRAC, iLO or any IPMI virtual media console — or flash it to a USB stick and boot from that.
- 02
Answer five prompts
NIC index, IP with prefix, gateway, hostname, root password. The gateway is calculated from the prefix; ENTER accepts it.
- 03
Pick an operating system
A review screen shows every field before anything is written. Fix what is wrong, then choose the OS entry.
- 04
Walk away
The machine fetches the vendor kernel and initrd, runs the install unattended, and reboots into a configured system with SSH root login.
Under the hood it is a single boot image carrying a custom CIDR parser and eight embedded payload files. At boot it pulls the official kernel and initrd for the chosen entry and appends the matching answer file to the initrd in memory — no vendor artefact is ever rebuilt or redistributed. Every installer is pointed at its boot interface by MAC address, so there is no interface-name guessing across hardware generations, and the answer files are named so that a manual install never auto-detects them.
What it needs, and where it stops.
Modern installers stage themselves in RAM, so the memory floor is set by the distribution rather than by this image. The rest is a short list, and we would rather you read it before the machine is racked than after.
Flashing to USB needs a hybrid MBR — virtual media, the intended path, is unaffected because the BMC presents the image as a CD. The repository documents how to verify a build before trusting a stick.
- Memory
- Ubuntu 22.04 and newer stream the full live image into RAM — 8 GB or more. AlmaLinux, Rocky and CentOS Stream need 4 GB for stage 2; Leap 16.0 needs 2.5 GB.
- CPU baseline
- AlmaLinux 10, Rocky Linux 10 and CentOS Stream 10 require x86_64-v3 (Haswell, EPYC or newer). Older Xeons should use the 9.x entries.
- Network
- The static address you enter must be able to reach the internet — every payload is pulled from the distribution mirrors at boot.
- Password charset
- The root password rides the kernel command line. Letters, digits and ._-!@#%^*+= are safe; avoid spaces, quotes, semicolons, slashes and backslashes.
- Hardware coverage
- Tested end to end so far on Ubuntu 24.04 with Dell iDRAC. The other entries share the same verified mechanics but deserve a smoke test on your own hardware.
Building it yourself needs only a container runtime; everything is pinned, and a rebuild takes about fifteen seconds after the first one.
FluxBilling does not use this ISO.
Inside the panel, bare-metal deployment and IP allocation are fully automated: an order allocates the address space, deploys the operating system and hands the customer a running server — nothing to attach, nothing to type.
But plenty of machines sit outside a panel: a box you are rebuilding, a one-off install, a rack you do not manage yet, someone else’s colocation. That is the job this image does, and we release it free because provisioning a server should not require a PXE stack or an afternoon of virtual media.
FluxBilling is billing, DCIM, IPAM and provisioning for hosting and colocation providers — one platform, one schema. The rack unit, the IP allocation and the invoice line that bills them are the same records.
- Bare-metal provisioningOrder to running server, with nobody in the loop.
- IPAMIPv4 and IPv6 allocated the moment a server ships, with rDNS.
- DCIMRacks, U-positions, power and BMC access in the billing database.
The installer, answered straight.
01.What is the FluxBilling OS Installer?
It is a free, open-source boot image — about 3 MB — that installs 19 server operating system entries unattended. You attach it over IPMI virtual media or a USB stick, answer five prompts (NIC, IP and prefix, gateway, hostname, root password), pick an entry, and the machine fetches the vendor kernel and initrd from the official mirrors and installs itself. It is published by FluxBilling under GPL-2.0-or-later.
02.Is it free, and do I need a FluxBilling account?
It is free, and no account is required. There is no licence key, no registration, no subscription and no telemetry — the repository is public and the ISO builds reproducibly from it with a single command. We publish it because provisioning a server should not require a PXE stack or an afternoon of virtual media.
03.Do I need a PXE server or DHCP to use it?
No. Static addressing is entered in the boot menu itself, which is the entire point: it works in a colocation rack where you do not control DHCP, and on a single machine where standing up a boot server would cost more than the install. There is also no private config webserver — installer identity and network configuration are generated on the machine itself from your answers.
04.Which operating systems can it install?
Nineteen entries across six distributions: Ubuntu 26.04 LTS, 25.10, 24.04 LTS and 22.04 LTS through the modern installer plus 20.04 and 18.04 through the legacy one; Debian 13, 12 and 11; AlmaLinux 10, 9 and 8; Rocky Linux 10, 9 and 8; CentOS Stream 10 and 9; and openSUSE Leap 15.6 and 16.0. Each family is driven by its own native answer file — cloud-init, preseed, kickstart, AutoYaST or Agama.
05.How do I install a server operating system over IPMI virtual media?
Mount the ISO as virtual media in iDRAC, iLO or your BMC console and boot from it. Enter the NIC index, the IP with its prefix, the gateway (pre-calculated, ENTER accepts it), the hostname and the root password. Review the summary screen, then pick the operating system entry. The install runs unattended and the machine reboots into a configured system with SSH root login. The whole console session is mirrored to serial (SOL), so it can be driven over a text-only out-of-band link.
06.Does it support UEFI, BIOS and /31 subnets?
Yes to all three. The image boots on both BIOS and UEFI, mirrors the console to serial for SOL access, and accepts any prefix from /1 to /31, including /31 point-to-point links. Every installer locates its boot interface by MAC address rather than by kernel-assigned name, so interface naming differences between hardware generations do not break the install.
07.Does FluxBilling itself use this ISO?
No. Inside the FluxBilling panel, bare-metal deployment and IP allocation are fully automated — there is nothing to attach and nothing to type. This image exists for the machines that sit outside a panel: a box you are rebuilding, a one-off install, a rack you do not manage yet, someone else’s colocation.
08.What licence is it released under?
GPL-2.0-or-later. The image is a modified iPXE binary distributed under the GNU GPL v2 or later with iPXE’s Unmodified Binary Distribution Licence exception; every modification is an explicit, reviewable step in the build files. No operating system is redistributed — kernels, initrds, install images and repositories are fetched unmodified from the vendors’ own mirrors at boot, and the answer file is injected into the vendor initrd in memory, on your machine.
Free, open source, and yours to fork.
Download the release, or clone the repository and build the exact same image yourself — everything is pinned and every modification is a reviewable step. Issues and pull requests are welcome.
Licensed under GPL-2.0-or-later. The image is a modified iPXE binary (copyright Michael Brown and contributors), distributed under the GNU GPL v2 or later with iPXE’s Unmodified Binary Distribution Licence exception. Corresponding source is the public repository. No operating system is redistributed: kernels, initrds, install images and repositories are fetched unmodified from the vendors’ own mirrors at boot.
Ubuntu is a trademark of Canonical Ltd; Debian of Software in the Public Interest, Inc; Red Hat and CentOS of Red Hat, Inc; AlmaLinux of the AlmaLinux OS Foundation; Rocky Linux of the Rocky Enterprise Software Foundation; openSUSE of SUSE LLC. All marks belong to their respective owners and are used descriptively to identify the operating systems this installer can fetch. This project is not affiliated with, sponsored by or endorsed by any of them, nor by the iPXE project.