Virtual Server FAQs

Here we answer list the Frequently Asked Questions for Virtual Servers.

What is a Virtual Server? Here is a short audio introduction [display_podcast]

A virtual server is an instance of an Operating System such as Windows 2022 running on a server with multiple other Operating Systems. This is possible by installing a hypervisor (software) on a physical server which enables many virtual servers to be loaded on the single physical server.

Why are there Virtual Servers?

For efficiency, many physical server are under utilized.  In other words they could be doing much more work.  Your email server might only be using 5% of the CPU.  So turning the email server into a virtual host server enables you to load a virtual server for your email and then other virtual servers for your file server, web server, database server etc.

Benefits of Virtual Servers:

  • As mentioned above you can fully use your physical servers by loading several virtual servers on a single server.
  • Increased uptime
    • Application Isolation  –  You can isolate each of your applications or servers.  One benefit is if one application errors it will not affect the others.  Also if you need to reboot one of the servers it will not affect the others examples include:
      • Web server
      • Application server (accounting application, file application)
      • Mail server
      • File server
      • Database server
    • Failover  –  Many of the hypervisor’s such as VMware enable you to set up hosting with multiple physical host servers for failover.  This increases your uptime by keeping your virtual server running even if the physical host running the virtual server fails.  The virtual server keeps running on another host.  Compare this to having to cluster physical webservers for redundancy.
  • Cost Savings
    • Better use of physical server capacity means you can have fewer servers (IBM commercial shows this).
    • Faster to setup, deploy and backup virtual servers saving you time which saves you money if you pay for these services.

What is a VPS?

VPS stands for Virtual Private Server (IE another term for Virtual Server). It is a virtual server setup for your exclusive use.

Limits of Virtual Servers

Sometimes a physical server is a better fit than a virtual server including:

  • High CPU usage applications – These would often consume most or all of the CPU available on a physical host server thus limiting the virtual servers on that host to 1.  Also some applications will not run as well on a virtual CPU compared to a physical CPU.  A virtual CPU (vCPU) is often limited to 1 or 2 Ghz which is less than many physical CPUs in dedicated servers.
  • The number of CPUs, RAM and Hard Drive Space are much more limited than on with a dedicated server.
    • CPUs  –  A virtual server might have a max of 4 virtual CPUs.  Compare that to an entry level dedicated server with a 6 core CPU or a more advanced server with 4 phyiscal CPUs each of them having 6 cores.
    • RAM  –  A virtual server could max out at 8G or 12GB of RAM where as many dedicated servers can have more than 200GB of RAM.
    • Hard Drive Space  –  Depending on the SAN the host server is attached to the virtual server may have more space available.

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