How to do virtualization on CentOS?

Madhu Desai · 08-15-2013, 07:51 AM

Is there any specific reason you don’t want to use virtualbox? Besides, KVM needs steep learning curve, and unless you are required to run full fledged virtual servers, i don’t see any reason to deploy kvm. Also, since KVM works great with kernel, linux virtual servers are best fit on it, although you can still use windows. Better solution for ms-windows vm is virtualbox or vmware player. both are free.

dt64 · 08-15-2013, 09:01 AM

Quote:

Originally Posted by Altiris

Ive discovered a problem, whenever I add BRIDGE=eth0 to the eth0 config file thats when everything or eth0 stops working. I tried it your way and my way (my way meaning I kept my default eth0 config but used your br0 config) and everything works, this is with leaving everything in the eth0 commented in the eth0 file. If I start commenting things out of the eth0 such as IP address etc then eth0 stps working which is normal because I havent bridged eth0 and br0. So basically, the problem is the BRIDGE=br0 command, whenever I do that everything gets messed up. I tried reinstalling the bridge-utils package and restarting my PC but I get the same problem. Any help?

Thanks for your help so far, the br0 config made it br0 work at least and show up in ifconfig.

You need to use:

Code:

BRIDGE=br0

in your eth0 file.
this assignes the interface to the bridge, hence it needs to be in the interface's config file.

dt64 · 08-15-2013, 09:07 AM

Quote:

Originally Posted by mddesai

Is there any specific reason you don’t want to use virtualbox? Besides, KVM needs steep learning curve, and unless you are required to run full fledged virtual servers, i don’t see any reason to deploy kvm. Also, since KVM works great with kernel, linux virtual servers are best fit on it, although you can still use windows. Better solution for ms-windows vm is virtualbox or vmware player. both are free.

KVM is more powerful than virtualbox or VMware and integrates better in Linux environment, especially in RHEL. It needs less ressource overhead as well.
This applies to Linux and Windows guests.

This my own personal experience from testing and using virtualization for a couple of years. (I've used VMware player/server/workstation, HyperV and ESXi as well)

Once you understood KVM it's nice to use as well, but I agree on your point, that the start is not plug n go like VMware player. (unless you are using standard NAT network config and vrt-manager with KVM, that would make it almost equal to VMware player)

Madhu Desai · 08-15-2013, 11:07 AM

@Altiris

I had enough experience in vmware and virtualbox to understand what i am doing. But still, when i started learning kvm, it was more than i bargained for. i spent a lot of time searching web and reading rhel official documentation to get the idea on how to run virtual machines in console (finally). During that period, i had made some small notes for my personal reference. i've attached those basic notes as attachment (kvm.pdf). you can go through them to get started.

Note (to mod): These are my own notes and i believe i'm allowed to share (no copyright issue). if any such issue, please let me know, i'll remove them.

Once you get the hang of it, following links are worth checking...
Set up RHCSA/RHCE Lab with CentOS
How clone a KVM virtual machine
Taking snapshots on KVM with libvirt
Booting From an ISO Image
Mounting and umounting a CD-ROM iso in KVM guests
How to manage networks in KVM

dt64 · 08-15-2013, 02:09 PM

@mddesai: nice reference!