In this blog post, we will explain the key differences between the physical and the virtual server from a customer’s perspective. We will also try to debunk some of the myths along the way. Hopefully, this will help individuals and companies make better decisions when purchasing a server.
Physical Server (a.k.a Dedicated Server)
A physical server is just as the name says, a server (physical computer) on which an Operating System, like Windows or Linux runs just as on any other computer. The physical servers are in almost all aspects like desktop computers, with many improvements that desktop PCs lack featuring things like redundant power supplies, raid controllers, multiple network cards etc. The physical servers are larger in size with much more powerful components in general. They all require a separate space in the server rack. Most of the servers also have two or more physical CPUs with multiple cores each.
Virtual server (a.k.a. VPS or a Virtual Machine – VM)
In order for everyone to understand the concept of virtual servers, we need to explain a little bit on how the virtualization works.
Hypervisor – An operating system or a software within the operating system that simulates a computer environment where the virtual machines are created and run from.
This means that the Hypervisor can be either a separate software (Type 2 Hypervisor) or an entire operating system can act as a Hypervisor (Type 1 – Hypervisor, also known as “Bare Metal Hypervisor” or “Embedded Hypervisor”). Examples of type 2 Hypervisors include Oracle Virtualbox, VMware Workstation and Microsoft VirtualPC. Examples of type 1 Hypervisors include VMware ESXi (vSphere), Microsoft Hyper-V, KVM, Xen and others. The latter – the type 1 Hypervisors – can all be installed just like an operating system is installed on the server. When a Hypervisor is installed on the server, its resources are equally distributed among the VMs, thus one server can host hundreds of VMs.
When a VM is created it behaves much like any other computer, you can power it on and load an operating system just as you would on any other computer. The OS is then tricked into thinking that it is run on a physical computer. Each VM has its own so-called virtual hardware. The VM has its own CPU, hard disks, and network interfaces. That means that a VM by default doesn’t know that it is a VM unless there is some software on it that will detect that using other means.
Physical vs Virtual servers pros and cons
Now that we understand the concept of the virtual servers we can make a general comparison of the both from a customer’s perspective.
Physical server cons
- Much more expensive than a virtual server (VPS)
Simply because of the resources needed to run and maintain a physical server, they are much more expensive.
- Harder to manage
The physical servers are overall much harder to manage. This is especially true with restorations in cases of failures. Just like every other machine, there will be a day when because of a number of reasons the server will fail. In these cases, restoration from backups is a true nightmare as the server will need to be rebuilt from scratch on another (new) server and then the data will have to be restored from the backups. For critical production systems, this means at least 8 or more hours of downtime. To prevent this the companies create clusters of two or more servers, but of course, this will just increase the expenses.
- Less scalable
It is almost impossible to do a server upgrade without additional downtime. Also, it is worth noting that the future upgrades for a dedicated server should be taken into account when ordering the server. Otherwise, the upgrades may lead to ordering a completely new server. That will instead lead to an unplanned service migration and thus unplanned service downtime.
Physical server pros
- More powerful than a virtual server
This is the only reason why someone would need to order a dedicated server. So let’s face it, if we have a physical server with 8 GB of RAM and a dual-core CPU, and make an exact virtual machine replica with the same parameters, the physical server will provide much better results. That is because the physical server will not suffer the performance bottlenecks that are present at the virtual machines.
Virtual server cons
- Lower performance compared with the dedicated servers
As it has been previously explained, the VMs offer slightly less performance than the physical servers because of a number of reason. Mainly the reason is a performance bottleneck that is between the VM and the hypervisor itself. In most of the cases, this is irrelevant because this drawback can be easily solved with making clusters of three or more virtual servers. Lastly, with the SSD drive technology coming into play the performance of the VMs has been greatly increased.
Virtual server pros
- Cheaper than a dedicated server
The physical servers where the VMs are located can host hundreds of VMs. The resources are then divided among the VMs and so the VMs take very little resources on the parent host thus greatly reducing their price.
- Simplified management
This is mainly the greatest advantage the VMs have over the physical servers. A VM is much easier to be managed than a physical server. For example, when installing a physical server one must perform a close-up inspection of the server’s hardware and its peripherals and verify that they are working correctly. If something is not working as intended, additional drivers should be installed and configured. When a VM is deployed, the VM takes its drivers from the parent host, thus the VM is ready for work immediately. And this is only one example of many.
- Simplified backup and restoration
Where on each physical server a manifest needs to be made of its configuration, applications and what should or shouldn’t be backed up, for the VMs, backups from the whole VMs are made. When a failure occurs for whatever reason, these backups are ready to be restored immediately and a whole VM is restored instead. It is obvious that in such cases downtimes are greatly reduced.
- Scalable and flexible
There is no downtime for performing resource (plan) upgrades with more RAM, CPU power, disk space etc.
- The perfect choice for hosting any web service
Whether it is a small blog or a large social network with thousands of visitors per day, the VPS can be easily adjusted to match the load. If needed, more VPSes can quickly and easily be added into a cluster serving different aspects of the web service.
Are Virtual Servers or Physical Servers Right for My Business?
Short answer – 99.9% of the time, a VPS is a better choice.
Virtualization as a technology these days is getting better and better. Almost every company worldwide has adopted the virtualization up to some level. Unless you need the real power of a dedicated server and you also have a large business budget, there is no other reason of why one should not choose a VPS. A VPS, especially if SSD based, is fast, secure and easy to manage.