What’s the difference and which one’s right for your business?
When the time comes to place your applications and workload in the cloud, the initial consideration is usually whether to select a virtual server or a dedicated server. In this article we examine both terms so you can make an informed decision about which one is right for your business.
In actual fact, most of the servers you will be offered by providers will be dedicated to your business, the difference is really between a physical machine and a virtual one that exists on a shared hardware platform. But before we get into the detail, let’s be clear about the jargon.
When most people say virtual server, they really mean virtual private server or VPS. A virtual private server is sometimes also called a shared server (somewhat misleading), a virtual machine (VM), a virtual managed server (VMS), which implies a management service is included, or simply a cloud server.
And when they say dedicated server they really mean dedicated physical server. Some may also call this a managed server – although again, this implies that management services are included.
Virtual private servers – perfect for some
In most respects, a VPS is functionally equivalent to a physical server. It’s a server which is created in software by a controlling agent, often called a hypervisor. The server exists on a fully shared infrastructure but its resources are solely at your disposal. There is no element of sharing taking place within the VPS, despite the fact that many VPS' can sit on the same, shared infrastructure.
A VPS can comprise any combination of CPU, RAM and storage capacity and can also run practically any OS. The CPU, RAM and storage resources available to VPS can be scaled up or down at any time.
VPS customers have super-user level access to the OS and can install almost any software they wish. Because multiple VPS' do exist on the same physical server, or node, its possible for the performance of one to affect another. At peak internet times for example, this can lead to saturation of the node resources which might result in a temporarily diminished performance for all servers.
What about security?
Security is often a concern for a business moving to the cloud, but it is often blown out of proportion. Security-wise, VPS', from reliable providers, are a very safe choice. The logical security capabilities of a VPS are no different from any other server and are entirely within your control. Physical security is somewhat different – being part of a shared infrastructure, there is no separation of physical devices. This could be perceived as a flaw but, in reality, it isn’t. All VPS' benefit from the physical security measures of the data centres in which they are housed.
In the case of ServerSpace, and most other Tier 3 data centre tenants, this includes biometric site and server suite access, locked server racks, CCTV and 24x7 security attendance, so there is really very little physical security risk.
Maintenance of shared platforms, like those that VPS’ run on, is a shared issue. Hosting providers take care of all maintenance related issues, patching software and replacing failed components for example. Fortunately VPS’ providers usually operate infrastructures that incorporate N+1 redundancy, meaning maintenance can normally take place without you experiencing any down time at all.
Dedicated Physical Servers offer even more power and control
A dedicated physical server is an individual server that is allocated to you in full. You have full and total access to its resources, including CPU, RAM and storage, and have complete control over its initial configuration so you can run any OS and application software you wish on it.
Performance of other machines can in no way affect the performance of your machine – so if its performance is slow, you know it’s the result of your own workloads, not others’.
The benefit of this dedication of physical resources is perhaps best observed when an application performs an extremely high volume of read and/or write actions to the hard disk – in a large database configuration for example. Under this scenario, having 100% access to the bus can be extremely helpful in maintaining performance and understanding/planning expansion requirements for the future.
Maintenance and security
Being physical, rather than virtual, means that upgrades or downgrades are physical too. This may mean that an upgrade requires you to wait for delivery of a server, or parts, and availability of an engineer, in a managed scenario, to install and configure them.
Logical and physical security of dedicated servers are much the same as VPS'. Since the physical server is dedicated to you, nobody has reason for physical contact with it unless conducting your business. And since we are still in the data centre environment, malicious physical access is extremely unlikely.
Management of a dedicated server differs from that of a VPS. For starters, it’s optional as to whether you perform basic management tasks or your provider does. A managed server from your provider will no doubt increase the price slightly but means they take care of applying basic software patches and replacing failed components.
How big is your budget?
As you can see, VPS and DS are in fact pretty similar propositions from a wide range of perspectives. So when is one more suitable than the other? First let’s look at the pros and cons:
A VPS is usually cheaper than an equivalent DS, highly configurable and relatively quick and easy to scale. But it exists on a shared platform, meaning that you do not have total control over the performance or maintenance schedule of the system. In very rare instances, you may not be able to run the combination of OS and application software that you need.
A DS may cost more than a VPS, though not always, but it is yours in full – performance and maintenance are within your control. However bear in mind that upgrading or changing the configuration of a DS may take longer due to the physical delivery and installation times.
How to recognise which server best suits your needs
Which type of server is right for you depends entirely on your individual requirements which need to be fully understood from every angle. Based on our years of experience with businesses of all shapes and sizes however, we can offer the following rules of thumb.
A Virtual Private Server is well suited to applications where performance, particularly hard disk read/write performance, is not particularly demanding but where the requirement for computing power is highly variable. These applications benefit from the ready scalability of a VPS.
A Dedicated Physical Server is well suited to applications with intensive disk usage, such as databases. These applications benefit from total access to device resources – allowing a higher performance ceiling and better planning. On the downside, a DS takes longer to reconfigure.
Get the best of both worlds
If you’re still torn between the two, it is entirely possible to combine VPS' and DS' into one system – in a hybrid cloud. For example, you could assign a VPS as a front end webserver and have a DS in the background crunching numbers on the database.
Hope that helps.