Guides
Running Multiple WordPress Sites on One VPS
2026-10-25 · OSIR Team
How many WordPress websites can you fit on a VPS? Anywhere from a couple to a hundred. What decides it is how much traffic those sites get and how fast they grow.
Most business sites are small and stay small. A company site with a dozen pages and a few hundred visits a day barely registers on a server, and you can run ten or twenty of them on a cheap box without any of them noticing the others. That part is easier than people expect.
The sites that cause problems are the ones that keep publishing. A blog that adds articles every week is also adding images, revisions, and a bigger backup every night. None of that shows up as load, so the server feels fine right up until the disk is full. On a small VPS, disk is what you run out of first, and it happens gradually enough that nobody is watching when it does.
How many per package
| Package | vCPU | RAM | SSD | Per month | Small business sites |
|---|---|---|---|---|---|
| OSIR-MINION | 1 | 512 MB | 10 GB | $1.99 | Too small for a control panel |
| OSIR-S-US / OSIR-S | 1 | 1 GB | 10 GB | $1.99 / $2.99 | 10 to 15 |
| OSIR-M | 2 | 2 GB | 25 GB | $3.99 | 20 to 40 |
| OSIR-L | 4 | 4 GB | 50 GB | $8.95 | 40 to 100 |
The one kind of site that breaks the numbers
Shops and membership sites are a different product. Logged-in pages cannot be cached, so every click goes through PHP and the database, and one reasonably busy WooCommerce store will use a 2 GB server on its own. Keep those off the shared box and size them individually.
Two settings worth getting right
If you are putting twenty sites on one server, these two are worth the ten minutes.
Use pm = ondemand on the PHP-FPM pools. The default keeps spare workers in memory for every site whether anyone is visiting or not, so twenty quiet sites can look like a memory problem that has nothing to do with traffic. With ondemand the workers start when a request arrives and exit when it goes quiet.
Turn off WordPress cron and use the system one. WordPress runs its scheduled jobs on page loads, which is fine for one site and messy across twenty. Add this to each wp-config.php and give every site its own cron entry at a different minute:
define( 'DISABLE_WP_CRON', true );
A page cache in front of everything means most visitors never reach PHP anyway.
Ordering the server and pointing the domains
Building the server is quick. Creating DNS records for twenty domains by hand is the part that takes the afternoon.
With the OSIR connector set up in Claude, both happen in the same conversation:
You: order a 2 GB VPS in Germany, hostname wp01, Ubuntu, with my SSH key and swap enabled
Claude: OSIR-M, 2 vCPU, 2 GB RAM, 25 GB SSD, Nuremberg. $3.99/month plus processing. Confirm and I'll place the order.
Once the server has an IP, the DNS is one more sentence:
You: point these at 203.0.113.10, apex and www: example.com, example2.com, example3.com
That works for domains held in your OSIR account. Domains parked elsewhere need their nameservers changed first, or the records added wherever they live now. If you would rather click through it, the VPS setup guide covers the same ground in the panel, and SSH access and keys covers getting into the box afterwards.
Virtualmin
Use Virtualmin GPL to manage the sites. It is free with no domain limit, and gives each site its own system user, database and Let's Encrypt certificate.
Install it with --type mini. A full install brings SpamAssassin, ClamAV, local mail and local DNS along with it and wants around 4 GB; the mini install keeps the web stack and skips all of that, which brings it down to around 1 GB.
Running mail on the same box as your sites is a poor trade anyway. It costs you memory, and a shared IP sending from forty WordPress installs is the fastest way to end up on a blocklist. Put it on OSIR email hosting instead: enabling a domain is free, you pay per mailbox, and if the domain already sits in your OSIR account the MX, SPF, DKIM and DMARC records publish themselves.
When you need something bigger
Our largest VPS is 4 GB with 50 GB of SSD. Beyond that we rent dedicated servers from $49 a month plus a one-off setup fee of the same amount, giving you 20 cores and 64 GB of ECC memory in Kansas City.
Check the disks before treating that as a straight upgrade. Those machines come with two 600 GB HDDs in RAID1, so you gain a great deal of space and memory but lose SSD latency. Behind a page cache nobody notices; for anything disk-heavy the 4 GB VPS can still feel quicker. Specifications are on the dedicated servers page, and scaling your VPS covers what carries over if you move up a package instead.
What you are taking on
Running your own box means nobody else is patching WordPress, watching the disk or checking that the backups work. Set up monitoring for free disk space on day one, because that is the failure you will actually hit, and restore a backup onto a spare server once so you know the process works before you need it at speed. Snapshots are the quickest way to take a whole-server restore point before you touch anything risky.
Bots will be a surprising share of traffic on small sites, sometimes more than the real visitors, so rate limiting is worth more than extra memory. Firewall rules are the other half of that.
And everything on the server shares a fate. One bad update or one full disk takes all forty sites offline together, which is an easy trade for your own projects and a conversation to have with a client before it is their business on there.
If the server is for your own work rather than hosting other people's sites, choosing a cheap VPS to develop on covers that side of it.
Multiple WordPress sites on a VPS FAQ
How many WordPress sites fit on a 2 GB VPS?
Twenty to forty small business sites with modest traffic, a page cache and mail handled elsewhere. The range depends on how much new content they publish, since that is what consumes the 25 GB of disk. One busy shop can use the whole server by itself.
What runs out first, memory or disk?
Disk, almost always, and it creeps up rather than arriving suddenly. Sites that publish regularly accumulate uploads, revisions and backups. Keeping backups off the server and capping upload sizes buys back most of it.
Is Virtualmin free?
Virtualmin GPL is, with no domain limit, including Let's Encrypt certificates and per-site accounts. Pro is a paid tier that adds commercial support, and you do not need it to host your own sites.
Can an agent order the server and create the DNS records?
Both, through the OSIR connector. Ordering a VPS and installing the OS are separate confirmed steps with the price shown first, and DNS records for domains in your OSIR account can be created in the same conversation.
Do I need a separate IP for each site?
No. Sites are served by hostname from one IP, and Let's Encrypt issues a certificate per domain.
What is the quickest win on a crowded server?
Switching the PHP-FPM pools to pm = ondemand. It stops every site holding idle workers in memory, which is usually what makes a server with twenty quiet sites feel short of RAM.
Current VPS packages and prices are on the VPS page.
Image generated with AI (Higgsfield).