Xen or OpenVZ?

[mouhuyjhakshys]

What are Xen and OpenVZ servers in web hosting?

I am seeing these in any offers from web hosting providers but i couldn't understand what they are?

 

[Hostlumina]

The difference between both are the following

OpenVZ - You are only able to run linux OS and you are unable to make any kernel modifications. So that means that all VPS within the host will rely on it's kernel.

One of it's disadvantages is that it can be oversold (i.e. Server has 8 GB of ram and you are able to create 15 VPS with 1 GB of ram each). This means that you run the risk of "slow downs" if all other VPS are using the memory.

XEN - VPS are not limited to the host kernel and you do not even have to run Linux. So in a way it's almost a mini "dedicated server" allowing you to install any OS such as Windows or BSD if you wished as you are not dependent of the main host.

Xen does not allow you to oversell, however this can technically be overwritten unfortunately. It is most likely that the provider does not oversell XEN allowing you to access that extra memory you aren't using as it is technically dedicated to the VPS.

 

[Adrianhenry]

OpenVZ - You are only able to run linux OS and you are unable to make any kernel modifications. So that means that all VPS within the host will rely on it's kernel.

I don't understand "kernel" term? what does it mean?

One of it's disadvantages is that it can be oversold (i.e. Server has 8 GB of ram and you are able to create 15 VPS with 1 GB of ram each). This means that you run the risk of "slow downs" if all other VPS are using the memory.

this means which VPS use more RAM then it will use RAM of others? while other VPS will be limited on number of RAM (8GB)?

 

[Hostlumina]

Kernel is the main system/module of an OS that loads first and then everything else loads. The kernel manages the memory, process and tasks, and disk management. It connects the system hardware to the application software.

Think about the Kernel as the heart of an OS.

https://en.wikipedia.org/wiki/Kernel_(operating_system)


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Well with 8GB of ram and 15 VPS @ 1 GB ram each... The resources (ram in this case) have to be shared among each other. If 8 VPS of those 15 are using 1GB ram at MAX for long periods of times every VPS will suffer during this time attempting to access whatever RAM required for their processes.

Think about it as a highway with only 2 lanes. The more cars merge into the highway those 2 lanes will become more congested with traffic and begin to slow down everyone and it can get to the point where you come to a complete stop.

 

[Sam150]

OpenVZ is cheap, good for start ups.