Differences between VM and real linux?

[vanpersie]

hi
what is the differences between working on linux virtual machine and
working with normal linux which installed directly on hardware ?

[Irithori]

Well, your question already contains the answer.
Access to real or virtualized hardware.

What you probably really asking is the consequences of that?
VMs do have advantages:
- snapshots
- easy migration between physical hosts
- easy to control resources: disks, CPUs, NICs, RAM
- out-of-band remote management built in (as long as you can connect at least to the hypervisor/physical host)

On the other hand, I wouldnt use a VM, if performance or simplicity has priority.
For example:
You cannot run a high performance database on a VM.
And I wouldnt run a production firewall on one either, because of the additional layer that may or may not alter the packets the firewall sees.


We use VMs to consolidate internal webtools, that dont justify a physical host each.
And VMs are also heavily used by our dev and qa teams.

[Rubberman]

I agree generally with what Irithori said, though with modern hardware that has direct virtualization support as well as multi-core processors, you can use a VM for all but the most performance demanding applications. IE, what he said about high performance database use is true, but for all but the most demanding DB uses, a VM may be a good route to take, especially if you may need to move the DB to another host - you can replicate the VM on another host, and no one will be the wiser. Only testing in a simulated production setting will tell you if you can use a VM for the database server, or not.

I run Linux as the host OS on all of my computers, and VM's for Windows, Solaris, QNX, and other Linux operating systems.

[jonyo]

linux is way easier to setup and run in vm, a cakewalk in comparison,

you have the option of basically dloading, sometimes unzipping then running linux OSs on the net