OpenPanel System Requirements: How Much RAM, CPU and Disk Do You Need?

This page lists the minimum requirements for installing OpenPanel and explains how to size a server for the number of websites and users you plan to host.

For an exact estimate for your setup, use the OpenPanel Resource Calculator.

Minimum Requirements​

Supported operating systems: Ubuntu 22.04, 24.04 and 26.04, Debian 10-13, AlmaLinux 9.5 and 10, Rocky Linux 9.6 and 10, CentOS 9.5. Ubuntu 24.04 is recommended. See the full list and known issues.

Not supported: Windows, macOS, shared hosting accounts, and container-based VPS (OpenVZ, LXC, Docker). The server must be a clean install with no other control panel or web server.

How OpenPanel Uses Resources​

OpenPanel runs every user's services (web server, PHP, database, caching) in that user's own isolated containers. This makes sizing more predictable than on traditional panels:

1. A fixed system base. The panel itself, the Caddy proxy, MySQL for panel data, Redis and optional services such as DNS, phpMyAdmin, email and malware scanning. Around 2-3 GB of RAM for a typical setup without email, around 1 GB more with email.
2. A small cost per idle user. An account whose sites get no traffic uses only about 15 MB of RAM and ~100 MB of disk (plus its website files, databases and emails).
3. Shared images, downloaded once. Web server, database and PHP images are stored once on disk and shared by every user - adding users doesn't multiply them.
4. Real usage from traffic. Busy sites use more CPU and RAM. Each user can be capped with plan limits, so one busy site can't take down the whole server.

Because most hosted sites are idle most of the time, one server can host far more accounts than the sum of their plan limits.

Quick Sizing Guide​

Rough starting points for RAM, assuming typical small websites (WordPress, PHP sites), Nginx + MariaDB, one PHP version and DNS enabled. The disk figures exclude your websites' own files, databases and emails - add those on top.

These are typical usage figures - most users idle, a few busy at the same time. Add headroom for busy sites: WooCommerce shops, forums and sites with heavy traffic can need 1 GB of RAM or more each on their own.

Using the Resource Calculator​

The calculator estimates CPU, RAM and disk from the options you choose:

• Number of users and the CPU / RAM limit per user from your hosting plans. The limits give the maximum if every user maxes out at once; the recommendation is based on typical usage.
• Database (MySQL or MariaDB), web server (Nginx, Apache, OpenResty, OpenLiteSpeed) and number of PHP versions - each adds shared disk space, and extra PHP versions add a little RAM.
• Caching (Redis, Valkey, Memcached) and cron.
• Add-ons: DNS, phpMyAdmin, email, FTP, ClamAV and ImunifyAV. ClamAV is the heaviest (about 4 GB of RAM) - use ImunifyAV if you're short on memory.

It also shows whether the setup fits the free Community edition or needs Enterprise. You can share the result - the settings are saved in the URL.

Other Things to Consider​

• Disk speed matters more than size. Use SSD or NVMe storage; databases and PHP are slow on HDDs.
• Swap. The installer creates a swap file automatically on servers with 32 GB of RAM or less. Swap prevents crashes during memory spikes but is not a replacement for RAM. See How to Add Swap.
• Backups need extra disk space (or remote storage) - see Configuring Backups.
• Email storage grows over time. Plan mailbox quotas, or store email on a remote server.

Related​

• Install OpenPanel
• How to find which site is using high CPU or RAM
• Suggested hosting plan limits