Hey there! Let’s break down the hardware and bandwidth requirements for your Moodle deployment based on your school’s scale—20k students, 250 courses, 700 staff, and 6k concurrent users. I’ll cover both standalone and clustered setups since you’re weighing those options.

If you’re going the single-server route (handling web, database, and cache all in one), here’s the minimum and recommended specs to keep things running smoothly:

• CPU: Minimum 16-core (32-thread) Xeon or EPYC processor. Moodle leans heavily on PHP execution and database queries, so more threads mean better handling of concurrent requests. For peak times like exam periods or first-day-of-class traffic, a 24-core (48-thread) chip would add extra safety.
• RAM: 64GB minimum, 128GB recommended. Each active user typically uses 8-12MB of PHP memory, plus you need space for database caching (MySQL/MariaDB buffer pools) and system overhead. 64GB will handle 6k users, but 128GB gives headroom for unexpected spikes and future course expansions.
• Storage: 1TB NVMe SSD minimum. Moodle does tons of random reads/writes (database queries, file uploads, resource access), so NVMe’s speed is non-negotiable here. If you have lots of multimedia content (videos, lecture recordings), add a 4-8TB NAS mount for secondary storage—keep the database and core Moodle files on the NVMe for optimal speed.
• Note: Standalone works for your scale, but it’s a single point of failure. If the server goes down, all users lose access immediately.

For better reliability, scalability, and fault tolerance, a clustered setup is the smarter long-term choice. Here’s how to split the workload:

Web Tier #

• 3-4 identical web servers, each with:
  • 8-core (16-thread) CPU
  • 32GB RAM
  • 512GB NVMe SSD
• Pair these with a load balancer (like NGINX or HAProxy) to distribute traffic evenly. If one web server fails, the others pick up the slack without disrupting service.

Database Tier #

• Primary Database Server: 16-core (32-thread) CPU, 64GB RAM, 1TB NVMe SSD. This handles all write operations (submitting assignments, updating grades).
• Secondary Database Server(s): 12-core (24-thread) CPU, 48GB RAM, 1TB NVMe SSD. Set up read replication here to offload database read requests (viewing courses, resources) from the primary. For even more resilience, consider a Galera Cluster for multi-master replication.

Cache Tier #

• Dedicated Redis or Memcached server: 8-core CPU, 16-32GB RAM. This stores session data, page caches, and frequent database queries—critical for reducing load on web and database servers.

Shared Storage #

• 4-8TB network-attached storage (NAS) with SSD or hybrid drives, mounted to all web servers. This stores course files, student uploads, and multimedia resources so all web servers can access the same content seamlessly.

Bandwidth depends on user activity, but here’s a realistic estimate for your scale:

• Concurrent Users: Each active user uses roughly 0.5-1Mbps (for page loads, images, and occasional video previews). For 6k concurrent users, that’s 3000-6000Mbps (3-6Gbps) of total bandwidth.
• Peak & Redundancy: Aim for at least 5Gbps to handle unexpected spikes (like exam submissions or first-day traffic). If you plan to host live lectures or large video files, bump this to 10Gbps.
• Upstream Bandwidth: Don’t forget uploads—students submitting assignments, staff uploading course materials. You’ll need at least 1Gbps upstream, with 2Gbps being ideal for heavy upload periods.

• Enable Moodle’s built-in caching (use Redis/Memcached as the backend) to cut down on repeated database hits.
• Compress static resources (CSS, JS, images) and use browser caching to reduce unnecessary downloads.
• Clean up old data regularly—archive finished courses, delete unused files, and optimize database tables.
• Set up monitoring tools (like Prometheus + Grafana) to track CPU, RAM, disk I/O, and bandwidth usage—this helps you spot bottlenecks before they become problems.

内容的提问来源于stack exchange，提问作者Mr. Sinko