I already have a server for one of my communities, using Hetzner Cloud. Since I’m just starting out, there’s not enough traffic yet and even when it starts growing, the initial traffic will not be enough that justifies 2 servers. I wanted to spend some time building the community without having to spend extra money, if I don’t have to, especially because I don’t even know when it really justifies 2 servers. Even at a low price of $5 a month, if it takes me 10 months to get to a point where the traffic justifies a separate server, that’s $50 that I could save and use for something else. Can I use a single server for 2 Discourse installations? I’m thinking that maybe there’s some conflict because of the IP, but since I’m not an expert, I don’t know the options? Any tips? Thanks!

[image] pfaffman: just 1gb of ram The cx23 has 4gb ram. I’m moving my other two sites to their separate cx23 servers so we’ll see how this plays out, but my feeling is it will be a-ok. [image] pfaffman: only if they all use the same smtp credentials. I am confused by this as mail-receiver is just about receiving email and there are no smtp credentials. Are you talking about incoming or outgoing email? With outgoing email does not each site have its own smtp credentials configured in app.yml?

[image] tobiaseigen: I am confused by this as mail-receiver is just about receiving email and there are no smtp credentials. No. Mail receiver is separate. If you’re using multisite, then there is just one YML file and that’s where the SMTP sending credentials are set. If you’re using mail receiver, you’ve got a different issue, as you need a mail receiver for each site (at least, that’s the only solution I’ve found.

Right. That makes sense. And I think would be fine for me using mailgun. I will understand all of this better if and when I start setting up a multisite!

[image] itsbhanusharma: You’ll first have to decide whether you want a single multisite or a single server hosting multiple standalone sites. Jumping in because I’m in a similar situation as @alltiagocom — I’ve got discourse installed on a smallish Hetzner server for my main community but have been thinking, in the background, of moving a few other Facebook groups to Discourse once I have got the hang of things. I’m familiar with « Wordpress multisite » but I’ve understood that Discourse multisite is more involved. I was wondering what would be less of a headache, running two standalone sites (or more) or a multisite. Any insight on this?

Multisite would definitely be less maintenance overhead so less headaches but YMMV

For Discourse novices, I recommend just running two sites. I made a topic for how to run multisite without a reverse proxy, but it’s out of date now. I think all that needs to change is [image]Setup Multisite Configuration with Let's Encrypt and no Reverse Proxy # tell letsencrypt what additional certs to get - replace: filename: "/etc/runit/1.d/letsencrypt" from: /-d example.com / to: "-d example.com -d two.example.com -d three.example.com" global: true can be replaced with the new DISCOURSE_HOSTNAME_ALIASES: domain.com,other.domain.com

My two cents, after spending the whole day working on this with the help of my old notes, ChatGPT, Claude, Discourse’s AI Bot, and some topics shared here (and after taking notes and more notes about the whole process). Everything seemed to be working just fine until I got to the point where I needed to add the reverse proxy. My first instance, which was working fine, wasn’t working. I asked a few more questions to Discourse’s AI bot, but since that’s my first day, it stopped working. It’s a limitation for new users of the bot. Claude, who was being super helpful, also stopped, because I’m on the free version. ChatGPT is the least reliable of all, so all replies from it, are always received by me with a LOT of hesitance… Then I came to the forum again and started reading a few topics about it, some written by @pfaffman. That was the last straw. Too complex, too much technical terms for me to even understand what to ask. Summary: my first instance was working, so I’m reverting it back to what it was (editing the app.yml file to what it was before the changes. I’m rebuilding as I type. To be honest, for all the complexity, even though it would allow me add more communities after going through the first big obstacle, I don’t think that saving $4 a month for an extra community will be the end of the world. Since I already know how to set up a server in Hetzner and then install Discourse, I will stick to 2 communities now, pay the $8 for both, and move on. Considering I was paying $12 for one droplet with Digital Ocean a few months ago, I can do the effort of paying the same amount for 3 communities if I want to. Regardless, I always find these adventures interesting, because I learn something new along the way, and in the end, at least I can say why I don’t want to do it, rather than just saying “I won’t do it, because I don’t know if I can do it”. I appreciate the time and help all of you shared here, and hopefully this topic will help others who want to achieve what I was trying to. :raising_hands: Over and out!

This is exactly why I said You need to rethink your strategy, while what you were trying to achieve wasn’t impossible, because it has been done before, it requires significant understanding of discourse to be able to get right. I’d recommend keep experimenting in your free time if you want to learn more about how discourse works, that’s how most of us here learned it.

[image] itsbhanusharma: I’d recommend keep experimenting in your free time if you want to learn more about how discourse works, that’s how most of us here learned it. It took me much longer than I care to admit to (mostly) figure it out!

I’m documenting a supported Discourse multisite install as a command-by-command runbook. I previously experimented with a “multiple standalone installs on one server” approach, but that configuration is not supported. This post focuses only on the supported multisite architecture, rewritten in a linear format for people who prefer explicit steps. What this is (supported) One Discourse app container (app) Multisite enabled via multisite.yml Shared Postgres + Redis (managed by Discourse) Connectivity via unix sockets (no Docker network required) Multiple hostnames routed to separate sites internally What this is not Multiple independent Discourse containers behind HAProxy Rolling rebuilds by draining app nodes Per-site SMTP credentials (SMTP is shared) Operational notes (so expectations are correct) Rebuilds / downtime In multisite there is only one app container, so ./launcher rebuild app will restart the only node. That means short downtime for all sites is expected. Certificates / host validation Add all hostnames to DISCOURSE_HOSTNAME_ALIASES so Let’s Encrypt + host validation work reliably. Backups / migration later Each site makes its own backup in /admin/backups. Restoring a site backup onto a standalone install later is the normal migration path. Full supported multisite runbook (command-by-command) 0) Host prerequisites Step Command Update system apt-get update && apt-get upgrade -y Install dependencies apt-get install -y git curl sudo 1) Install Discourse Docker Step Command Clone repo git clone https://github.com/discourse/discourse_docker.git /var/discourse Enter dir cd /var/discourse 2) Install first site (single site first) Step Command Run setup ./discourse-setup This creates /var/discourse/containers/app.yml and boots the first hostname (e.g. forum1.example.com). 3) Enable multisite Step Command Create config dir mkdir -p /var/discourse/config Edit multisite file nano /var/discourse/config/multisite.yml Example multisite.yml: forum1: host_names: - forum1.example.com forum2: host_names: - forum2.example.com 4) Edit app.yml to enable multisite + hostname aliases Step Command Edit app.yml nano /var/discourse/containers/app.yml Add: DISCOURSE_MULTISITE: true DISCOURSE_HOSTNAME_ALIASES: forum1.example.com,forum2.example.com 5) Rebuild Step Command Rebuild ./launcher rebuild app 6) Migrate multisite DBs Step Command Enter container ./launcher enter app Run multisite migrate rails multisite:migrate Exit exit Step Command Restart ./launcher restart app 7) Verify Visit: https://forum1.example.com https://forum2.example.com Each site has its own admin, users, uploads, and backups. 8) Backups / migration later Per-site admin: /admin/backups Restore that backup onto a standalone install later if you want to split the site onto its own server. If anything above conflicts with current best practice, I’m happy to update this runbook - the intent is to provide a linear supported multisite checklist that reduces trial-and-error.

Un seul serveur pour 2 communautés Discourse ?

Assistance produit Installation

pfaffman (Jay Pfaffman) Janvier 7, 2026, 6:29 50

Il m’a fallu beaucoup plus de temps que je ne veux l’admettre pour (principalement) le comprendre !

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Un seul serveur pour 2 communautés Discourse ?

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