KVM hosting

KVM (Kernel-based Virtual Machine) is full hardware virtualization technology creating isolated virtual machines with own OS kernels. OpenVZ is container virtualization where all users share common host system kernel. Main KVM differences: full isolation (neighbors' problems don't affect you), own Linux kernel (can update, configure), support for any OS including Windows, guaranteed resources without overselling, ability to run Docker/containers inside VPS. OpenVZ cheaper and lighter but limited to single system kernel, doesn't support Windows, providers often oversell resources. For production projects KVM more reliable and predictable.

Yes, KVM supports Windows Server (2012, 2016, 2019, 2022) and desktop Windows (10, 11) installation natively. KVM emulates full virtual hardware with BIOS/UEFI, network card, disk controllers—Windows identifies VPS as regular physical server. For maximum performance virtio drivers used (disk and network acceleration). Installation process: load Windows ISO image, mount through control panel, install like regular computer. Windows license purchased separately or provided by provider for additional fee (usually 10-15€/month). On OpenVZ or other container technologies Windows installation technically impossible.

KVM provides near-native performance—95-98% of physical server. Intel VT-x/AMD-V hardware virtualization technologies allow guest OS to execute processor instructions directly without software emulation. Disk operations accelerated by virtio drivers, network stack optimized. Main overhead (2-5%) related to hypervisor managing resource access. In practice difference unnoticeable for most applications. OpenVZ theoretically faster (fewer abstractions) but practically KVM more stable due to no resource competition with neighbors. For high-load databases, web servers, computational tasks KVM preferable. Performance loss critical only for specific tasks like HFT trading where every microsecond matters.

Yes, KVM VPS usually 20-50% more expensive than OpenVZ with same formal specifications. Reason—real isolation and no overselling. Provider cannot sell 10 VPS with 4 GB RAM on server with 16 GB physical memory (as done with OpenVZ). On KVM 40 GB virtual RAM requires minimum 40 GB physical. Typical prices: OpenVZ 2 GB RAM for 3-5€/month, KVM 2 GB RAM for 5-8€/month. Difference compensated by stability—on OpenVZ may encounter "neighbors" consuming all resources during peak hours. On KVM this won't happen—your 2 GB always fully available. For production projects overpayment justified by work predictability.

KVM mandatory for: Windows Server and applications (1C, MS SQL, Exchange, Active Directory)—OpenVZ doesn't support Windows at all. Custom kernel modules and drivers—VPN with WireGuard, specific firewalls, low-level network settings. Docker/Kubernetes production clusters—nested virtualization on OpenVZ works unstably. Security requirement projects—medicine, finance, government sector require virtual machine level isolation. High-load databases—PostgreSQL, MySQL, MongoDB work more stable with KVM guaranteed resources. For simple sites, small projects, dev/test environments OpenVZ sufficient and more economical. But for serious production projects KVM more reliable.