Cons of Dedicated servers / Pros of VPS
Storage maintenance

On a dedicated server, someone has to maintain the storage and check that everything is alright. For example, the admin of the web server must build, monitor and maintain this RAID storage. Many issues can be related to the remote maintenance of the storage. For example, after an SSD or Hard drive replacement, the Linux OS may refuse to boot because some the admin forgot to perform some actions. On the other hand, with a VPS server, the customer does not have to take care of the storage. It is fully managed by the web hosting company. However, you will later on in this article why it is not that simple.
Network adapter
On a dedicated server, the network administrator must check that the network adapter is well configured otherwise it could lose access to the dedicated server. It can be a major problem if the hosting company does not provide a different way to access the server. For example, if there is no console access to the server via VNC, the customer may lose it access to the dedicated server. On the other hand, on a VPS server, the web hosting company manages the network adapter configuration. Most of the time, they also provide an additional console access to the VPS server so that even if you misconfigure your VPS server, you can gain access using the console.
IP address theft
On a network, when the dedicated server is rebooting, another web server can steal the IP address of the dedicated server. This happens when someone else has misconfigured his web server or if someone wants to an IP address of a dedicated server to send spam to people. On the other hand, on VPS servers, the web hosting company manages the IP addresses of the VPS servers.
Cons of VPS server / Pros of dedicated server
Shared network adapter
When there are 10 VPS servers on a bare metal server, all the internet packets have to go through one network adapter. Consequently, one VPS customer may receive a high web traffic peak and block websites from other customers without them to be able to do anything about it. From our observation, this can be a cyclic and brief issue so that VPS customers may not be aware that it happens. For example, one VPS customer is located in the USA and another one is located in Europe.
On the other hand, with a dedicated server, there is only one user using the network adapter.
Shared resources
When you use a dedicated hosting, you know that you use 100% of the hardware from a bare metal server. Consequently, there is no other website running somewhere else stealing your server resources. A dedicated server is theoretically more stable than a VPS server. On the VPS server, the resources (CPU, Storage, memory) are split up between several customers. By the past, when you owned a VPS server, you could see speed or page load slow-down when websites from other customers received more requests. I must admit that today this is less visible. Nevertheless, I can still perceive very slight slow-down of page load and latency increase from websites hosted on VPS server.
Early aging of SSD & HD drive
When a server uses an SSD drive or an HR drive a lot in
On the other hand, if you subscribe to a brand new dedicated server, it is not likely that drives stop functioning if you are the only one using them.
Dedicated servers: what you see is what you get
When you are responsible for the whole web server, you take the responsibility of managing the web server. It comes with disadvantages and advantages. If you have a VPS server, the network admins of your web hosting company have to be good because your websites rely on their job quality. If you decide to subscribe to a dedicated server, you can do everything on your own and you don’t need to rely on other people. Nevertheless, in order to achieve this, you must know a lot about the OS of your dedicated server, Linux or MS Windows. If you don’t know Linux or Windows server, it is better to choose a VPS server.