Bare Metal Hosting

Bare metal servers provide single-tenant, dedicated hardware with no underlying hypervisor. This eliminates the hypervisor attack surface and the risk of VM escape or noisy neighbor attacks from co-located virtual machines. Security is enforced by physical separation, making it ideal for workloads with stringent compliance requirements (e.g., HIPAA, PCI-DSS, FedRAMP).

The tenant assumes the full security stack responsibility from the hardware firmware (BIOS/UEFI) and operating system up through the application layer. This includes:

• Firmware Security: Managing BIOS/UEFI settings, secure boot, and hardware root-of-trust (e.g., TPM).
• OS Hardening: Patching, configuration management, and user access controls.
• Network Security: Configuring host-based firewalls (iptables, Windows Firewall) and intrusion detection systems (HIDS).

Physical access control is delegated to the hosting provider. Key considerations include:

• Data Center Security: Provider's compliance with standards like SOC 2, ISO 27001 for physical access, surveillance, and environmental controls.
• Hardware Integrity: Assurance against hardware tampering or supply chain attacks (e.g., malicious implants).
• Decommissioning: Provider's processes for secure data sanitization (e.g., NIST 800-88) upon server retirement.

While the host OS can be fully controlled, network-level protections are often shared with the provider.

• DDoS Mitigation: Reliance on the provider's upstream network scrubbing services to absorb volumetric attacks.
• Network Segmentation: Use of VLANs, private networking, and hardware firewalls (if offered) to isolate the bare metal server within the provider's network.
• Egress Filtering: Controlling outbound traffic to prevent the server from being used as part of a botnet.

The lack of provider-managed hypervisor visibility shifts monitoring duties to the tenant.

• Telemetry Collection: Must implement agent-based monitoring for logs, metrics, and security events (e.g., using osquery, Wazuh, commercial EDR).
• Forensic Readiness: Ensuring adequate logging and storage for post-incident analysis, as the provider typically cannot access the server's disk or memory.
• Response Playbooks: Tenant is responsible for containment, eradication, and recovery procedures during a security incident.

Shared Responsibility Model Shift: In cloud (IaaS), the provider secures the hypervisor and physical layer. In bare metal, the tenant's responsibility extends downward to the firmware.

• Attack Surface: Cloud: Hypervisor + Guest OS. Bare Metal: Only the Host OS.
• Isolation: Cloud: Logical (virtual). Bare Metal: Physical.
• Management Overhead: Cloud: Lower for infrastructure. Bare Metal: Higher, requiring in-house expertise for full-stack security.

A virtualized server environment where a single physical machine is partitioned into multiple isolated virtual machines using a hypervisor. Each VPS runs its own operating system and can be rebooted independently, but shares the underlying hardware resources (CPU, RAM, storage) with other VPS instances on the same host.

• Key Difference from Bare Metal: VPS offers virtualization, leading to potential "noisy neighbor" effects where one tenant's resource consumption can impact others. Bare metal provides dedicated, unshared hardware.

A physical server leased to a single tenant, providing exclusive access to all hardware resources. It is the traditional precursor to modern bare metal hosting.

• Evolution to Bare Metal: Modern bare metal cloud services automate the provisioning, scaling, and management of dedicated servers through APIs and orchestration tools, offering the isolation of a dedicated server with the agility of cloud computing.

The virtualization software (e.g., VMware ESXi, KVM, Hyper-V) that creates and runs virtual machines. It sits between the hardware and the operating systems, managing resource allocation for VMs.

• Relation to Bare Metal: Bare metal hosting operates without a hypervisor (Type 1) for the tenant's workload. The server's OS runs directly on the hardware, eliminating the performance overhead and abstraction layer introduced by virtualization, which is critical for latency-sensitive applications like high-frequency trading or blockchain consensus.

A cloud computing model that provides virtualized computing resources over the internet. IaaS is typically associated with virtualized instances (like AWS EC2).

• Bare Metal as IaaS: Bare metal servers are now offered as an IaaS product (e.g., IBM Cloud Bare Metal, Oracle Cloud Bare Metal). They provide the same on-demand, pay-as-you-go, API-driven provisioning as virtual IaaS, but deliver physical servers instead of virtual ones, filling a niche for performance-intensive and compliance-driven workloads.

An OS-level virtualization method to deploy and run distributed applications within isolated user-space instances called containers (e.g., Docker, Kubernetes pods).

• Synergy with Bare Metal: Known as "bare metal Kubernetes" or container-native infrastructure. Running container orchestration platforms directly on bare metal servers maximizes performance for microservices architectures by removing the hypervisor overhead, providing predictable networking, and allowing direct hardware access for GPU or FPGA-accelerated workloads.

A distributed computing paradigm that brings computation and data storage closer to the location where it is needed, reducing latency and bandwidth use.

• Bare Metal's Role: Bare metal servers are often deployed at edge locations (e.g., colocation facilities, cell towers) because they provide a stable, high-performance, and secure platform for running critical edge applications—such as real-time analytics, IoT aggregation, or content delivery network (CDN) nodes—without the variability of shared virtualized environments.