Hi,
do you think that this is a good command to run on our vps?
May I broke something by running this command on my VPS?

if no, how often should I launch this command?
is there some other commands to keep my system updated if I install software only using yum?

There's really nothing magically different about a VPS. As far as the software inside the VPS is concerned, it's hardware.

The kernel is the exception to this, but Linode manages everything to do with the kernel automatically, so unless you've configured your Linode account for pv-grub, nothing that CentOS does with kernels will have any effect.

Basically, do whatever you would normally do to manage a server.

is there some advice that you can give me on how to mantain a VPS?

I think you're asking the wrong question. It sounds like what you should be asking is "how do I maintain a server". The fact that it's a VPS as opposed to a piece of hardware is not relevant. That may help you as you Google for answers.

Here's a guide that Google turned up; maybe it will be helpful.

http://www.ixibo.com/2008/11/learn-to-m ... ux-server/