Differences between Virtual Private Servers and Dedicated Servers

This article describes the differences between a Linux VPS and a Linux Dedicated Server from the perspective of Linux system administration and basic functionality. The information presented here is not all-inclusive, nor will the technology behind these differences be discussed.

Linux system administrators seeking a comprehensive guide to their virtualization platform of choice should consult the OpenVZ Documentation or Xen Documentation.

Fundamental Differences

The following differences can be noted on either the OpenVZ or Xen virtualization platforms:

Kernel and Hardware Differences

• Modified kernels are not supported at VPSLink
• All hardware is virtualized - Hardware clock may not be modified

Hardware clock workaround: VPSLink runs NTP on all hardware nodes to ensure server time is reported accurately. Setting the Linux System Timezone is a reliable way to synchronize your VPS time with your local time.

Network Interfaces and Hostname Reset on Reboot

• Network interface changes are reset when the VPS is rebooted
• Server hostname is reset when the VPS is rebooted

Configuration reset workaround: Add configuration commands to your /etc/rc.local file to reconfigure your VPS whenever it is booted.

OpenVZ Platform-Specific Differences

• C libraries may not be modified on OpenVZ
• Resolver nameservers are reset on reboot
• Kernel modules may not be installed and installed kernel modules are not visible within the virtual environment (see VPSLink OpenVZ Installed Kernel Modules for details)

Any allocations in excess of your VPS memory limit (RAM) will result in processes being killed on OpenVZ - please see the Problem: Process or Daemon Dies article for more information on OpenVZ's behavior and troubleshooting.

Xen Platform-Specific Differences

• C libraries may not be modified on Xen unless the modification is performed on a non-thread local copy of the compiler