Virtualization technology at cdmon: how our servers work

Server virtualization is the foundation of modern hosting. It allows scaling, resource optimization, and ensures stability.

Today, websites need speed, availability, and constant flexibility. And that is only possible with a well-designed virtualized infrastructure.

Brief context of modern hosting: scalability and demand

Web traffic is no longer stable. There are constant peaks.
An online store can multiply visits in minutes.

Therefore, current hosting must be:

• Scalable in real-time
• Capable of supporting high concurrency
• Flexible in resources (CPU, RAM, storage)

This is where virtualization technology comes in.

Article objective: explain the technical stack and benefits for clients

In this article, we explain:

• How our cdmon hardware virtualization works
• What technologies we use (hypervisor, cluster, NVMe)
• How we ensure performance, scaling, and high availability

What is server virtualization? (key concepts)

Server virtualization is the creation of multiple virtual machines within a physical server.

Each one functions as an independent server.

Simple definition: virtual machines vs physical servers

• Physical server: real machine with dedicated hardware
• Virtual server: isolated environment within that hardware

Example:
A single physical server can host several virtual servers, each with its own operating system.

Main components

To understand virtualization, there are three key pieces:

• Hypervisor: software that creates and manages virtual machines
• Physical host: the real server where everything runs
• Guest OS: operating system of each virtual machine

Examples of hypervisor:

• KVM
• VMware
• Xen

Types of virtualization

There are several approaches:

• Full virtualization: completely simulates the hardware
• Paravirtualization: optimizes communication with the system

Architecture used in cdmon (overview)

Our infrastructure combines virtualization, clustering, and high-performance storage.

Chosen hypervisor and why

At cdmon, we work with technologies like Xen and KVM, which offer:

• Complete isolation between clients
• Guaranteed resources (no overselling)
• High performance and stability

Quick comparison VMware vs KVM:

• KVM: more flexible, open source
• VMware: more closed, but widely used
• Xen: balance between performance and isolation

Cluster topology

We do not use isolated servers. We work with a cluster of servers.

This means:

• Several connected nodes
• Shared resources
• Centralized management

Benefits:

• High server availability
• Automatic load balancing
• Horizontal scalability

Storage and networking

Our infrastructure includes:

• High-speed NVMe storage
• Distributed systems (SAN / virtualized storage)
• Software-defined networks (SDN)

This allows:

• Lower latency
• Higher throughput
• Network flexibility

High availability and fault tolerance

If a node fails, the system responds automatically.

We use:

• Data replication
• Automatic failover
• Virtual machine relocation

Result:
Your service continues to operate without interruptions.

Storage: how we manage I/O and data

The performance of a server largely depends on storage.

Advantages of NVMe over SSD

NVMe storage clearly improves performance:

• More IOPS
• Lower latency
• Higher read/write speed

Compared to traditional SSD:

• Up to 5-10 times faster

Replication and consistency strategies

To protect data, we use:

• Distributed RAID
• Replication between nodes
• Consistency systems

This ensures:

• High availability
• Data integrity
• Quick recovery

Integration with CDN and Object Storage

For static content:

• Use of CDN
• Integration with object storage

Benefits:

• Faster global load
• Less load on the server

Orchestration and management: scaling and deployment

Virtualization does not work without good orchestration.

Orchestration tools

We use technologies such as:

• Internal management systems
• Deployment automation

This allows managing hundreds of machines efficiently.

Autoscaling

The system adjusts resources automatically according to demand.

Example:

• Traffic peak → more CPU and RAM
• Traffic drop → resource reduction

Based on:

• Thresholds
• Automatic policies

Rapid provisioning

You can create a server in minutes:

• Instant deployment
• Snapshots
• Environment cloning

Security and isolation in virtualized environments

Each client is completely isolated.

Isolation between tenants

We apply:

• Virtual private networks
• VLAN
• Firewalls

Result:

• Total security between clients

Updates and hardening

The system is kept updated:

• Security patches
• Hypervisor hardening
• Constant monitoring

Backup and recovery

Includes:

• Automatic snapshots
• External copies
• Definition of RTO and RPO

Monitoring and SLO: how we ensure performance

We measure everything to ensure consistent performance.

Key metrics

We monitor:

• TTFB
• IOPS
• Latency
• CPU steal
• Memory ballooning

Tools

We use:

• Prometheus
• Grafana
• Zabbix
• Proprietary systems

SLA and support

We offer:

• High availability (>99.9%)
• Specialized technical support
• Quick response

Practical comparison: virtual servers vs dedicated servers

Not all projects need the same.

Use cases

Virtual servers:

• Ecommerce
• SaaS
• Development environments

Dedicated servers:

• Intensive databases
• Critical projects
• High constant consumption

Comparative table

Feature	Virtual server	Dedicated server
Cost	Lower and flexible	Higher
Scalability	High (automatic)	Limited
Performance	Very high (guaranteed resources)	Maximum
Control	High	Total
Maintenance	Managed optional	Greater responsibility

Best practices and recommendations for clients

Choosing the right configuration is key to performance.

How to choose resources

Consider:

• vCPU according to load
• RAM for applications
• Type of storage (NVMe recommended)

Staging tests

Before launching:

• Benchmarks
• Load tests
• Traffic simulation

Application optimization

Recommendations:

• Use of cache
• CDN
• Database optimization
• PHP adjustments

Conclusion

Server virtualization allows for faster, more flexible, and secure hosting.

At cdmon, we combine:

• Advanced virtualization technology
• NVMe storage
• Clustering and high availability
• Monitoring and automatic scaling

Result:

• More performance
• Greater availability
• Better cost

Frequently Asked Questions (FAQ)

What hypervisor does cdmon use?

We use technologies like Xen and KVM, which ensure isolation, performance, and stability.

How do you manage security between clients?

Through:

• Complete isolation
• Private networks
• Firewalls and VLANs

Can I migrate from a physical server without downtime?

It depends on the case, but we use techniques that minimize downtime.

What does NVMe mean and why is it important?

NVMe is a type of ultra-fast storage.
It reduces latency and improves overall performance.