How-to understand what VPS is

Apoc · #1 12-02-2005, 11:02 PM

It appears many people find it hard to understand what VPS is and how it works, so I just thought I'd make a small effort to explain a littlebit.

What does VPS mean?
Virtual Private Server

What is such a Virtual Server?
Basically VPS is all about running multiple Virtual Servers within one physical server.

What does Private refer to?
Each VPS gets its own portion of resources, which are usually guaranteed to be available to that particular VPS. For instance, the host server may have 8GB of ram, and 256mb (for instance) could be guaranteed to be available to a VPS. That would mean that regardless of what other VPS's on the same server use, that amount of RAM will be available to the VPS.

Also very important: each VPS runs completely independent of eachother. Each VPS has its own filesystem so a VPS can't see any of the data of another VPS. Also each VPS has it's own server load, can run its own Operating System, can be rebooted individually, and so on. Basically by the end user it can be treated as a dedicated server.

So does a VPS also have its own kernel?
Usually not, but it depends on the technology that the host uses.

Are VPS's truly 100% isolated from eachother, so no matter what happens they can not cause trouble to eachother?
Under normal circumstances, yes. However in extreme scenarios, VPS's can trouble eachother. For instance if the host server has a 100mbit uplink, and one VPS gets a 100mbit DDoS attack, then it makes sense that all other VPS's on the same server are also affected by it. It's up to the host to ensure maximum reliability by monitoring everything closely.

I mentioned VPS's on the same host server can each run a different Operating System. So could one VPS on the server run Windows, and another one Linux?
No, that's not possible. It is however possible to run different Linux distributions on a Linux VPS server. For instance one VPS could be running Red Hat Enterprise, and another one could be running Debian.

Is it possible to run anything on a VPS that would run on a dedicated server?
As long as it doesn't require kernel modifications, yes. (note: some technologies do support kernel modifications - that's not something I specialize in though)

For everyone who still has trouble understanding what VPS is, I thought of a nice example:

You could compare VPS technology to a block of apartments. The block has one roof, but under that roof there are multiple apartments. Each apartment has its own kitchen, living room, etc, so it can operate individually. Everyone goes in and out through the same door of the building though (VPS: traffic all goes through one network port). And I'm sure you can think of every other similarity.

beruska · #2 12-06-2005, 04:18 AM

Quote:

Originally Posted by Apoc

You could compare VPS technology to a block of apartments. The block has one roof, but under that roof there are multiple apartments. Each apartment has its own kitchen, living room, etc, so it can operate individually. Everyone goes in and out through the same door of the building though (VPS: traffic all goes through one network port). And I'm sure you can think of every other similarity.

Nice example

How about gas, electricity and water

Apoc · #3 12-06-2005, 07:48 AM

That could be compared to the resources like CPU, RAM and bandwidth - they come in through the same pipes and are then divided among apartments/vps's. There are probably a ton of other similarities to think of

Pyrox · #4 01-07-2006, 10:21 PM

Think of it as an appartment Block Each VPS in the Dedicated server is a Home, 1 Roof Many Homes

Kai J A · #5 01-22-2006, 06:08 PM

I'm definitely loving the example. Hahaha! Good tutorial mate.

zOrK · #6 01-24-2006, 04:06 AM

ahaha! It couldnt be better!, nice tutorial.

anythinghosts · #7 02-12-2006, 07:53 PM

nice insight, very useful for people who dont know this shaded sector of hosting

Rebel007 · #8 03-22-2006, 07:50 PM

Very helpful indeed, I realise I am a latecomer to this thread but, I am a new member on this forum as well.

KnownHost · #9 03-22-2006, 07:53 PM

Before ever buying a VPS research who you are buying it from. Way too much risk otherwise. That is my two cents. Also, look for someone who puts customers first as in the game of hosting that is not the case with many. Being able to support your customers is all that really matters as that is where people fail.

-Jay

ferdy · #10 03-30-2006, 03:36 AM

Great work man.
Simply awesome example

Quote:

Originally Posted by Apoc

It appears many people find it hard to understand what VPS is and how it works, so I just thought I'd make a small effort to explain a littlebit.

What does VPS mean?
Virtual Private Server

What is such a Virtual Server?
Basically VPS is all about running multiple Virtual Servers within one physical server.

What does Private refer to?
Each VPS gets its own portion of resources, which are usually guaranteed to be available to that particular VPS. For instance, the host server may have 8GB of ram, and 256mb (for instance) could be guaranteed to be available to a VPS. That would mean that regardless of what other VPS's on the same server use, that amount of RAM will be available to the VPS.

Also very important: each VPS runs completely independent of eachother. Each VPS has its own filesystem so a VPS can't see any of the data of another VPS. Also each VPS has it's own server load, can run its own Operating System, can be rebooted individually, and so on. Basically by the end user it can be treated as a dedicated server.

So does a VPS also have its own kernel?
Usually not, but it depends on the technology that the host uses.

Are VPS's truly 100% isolated from eachother, so no matter what happens they can not cause trouble to eachother?
Under normal circumstances, yes. However in extreme scenarios, VPS's can trouble eachother. For instance if the host server has a 100mbit uplink, and one VPS gets a 100mbit DDoS attack, then it makes sense that all other VPS's on the same server are also affected by it. It's up to the host to ensure maximum reliability by monitoring everything closely.

I mentioned VPS's on the same host server can each run a different Operating System. So could one VPS on the server run Windows, and another one Linux?
No, that's not possible. It is however possible to run different Linux distributions on a Linux VPS server. For instance one VPS could be running Red Hat Enterprise, and another one could be running Debian.

Is it possible to run anything on a VPS that would run on a dedicated server?
As long as it doesn't require kernel modifications, yes. (note: some technologies do support kernel modifications - that's not something I specialize in though)

For everyone who still has trouble understanding what VPS is, I thought of a nice example:

You could compare VPS technology to a block of apartments. The block has one roof, but under that roof there are multiple apartments. Each apartment has its own kitchen, living room, etc, so it can operate individually. Everyone goes in and out through the same door of the building though (VPS: traffic all goes through one network port). And I'm sure you can think of every other similarity.

detox host · #11 03-30-2006, 05:21 PM

Very nicely explained man.

wa1nut · #12 04-01-2006, 07:13 PM

theres a program i think people who do vps should install, i cannot remember the name of it but it makes certain computers have a certain amount of connection to the internet on a router, the program is installed on the computer and is then passworded by the admin to stop people using up all the bandwidth, also if you're really cheaky you can have it on one computer (aka the server) and limit what uses how much connection without people being able to access it. That would a) cut down on monitoring b) make sure people get the connection they are guarenteed