Hi,

I've a desktop computer that I want to install linux in it. But this computer will not have keyboard, monitor or mouse connected. I will only access the computer with SSH or VNC

Is it possible to run a computer without keyboard, mouse and monitor connected?

Sure. I run and use numerous hosts that way. You will probably need the keyboard and monitor to perform the installation. All of my headless hosts boot a mostly hand-crafted Linux that is loaded at boot time from a PXE server.

--- rod.

but this work with ubuntu, or I need another linux version?

This will work with any distribution. If you want to use Ubuntu I would recommend to run the server version, it comes without GUI. Running a GUI on a headless machine is somewhat pointless and a waste of resources.

While it may be uncommon to do so, it is perfectly satisfactory to use a remote X server to run GUI applications on a headless host. I do that all the time; it is a standard arrangement in my workplace. Running a full desktop on a headless server, and using a remote X server probably makes less sense, although I have done that, too, just for the sake of seeing whether it works (it did, with KDE3).
Installing unused applications of any sort, GUI or not, could be considered a waste of resources (disk). I find the most precious resource these days is human time, and I will happily trade a few GB of disk to save an hour of my time.

--- rod.

OK, but you will only need a few X packages (and may be QT,GTK+ or any other GUI framework), which will autumatically be pulled in when installing a GUI application. Therefore the server edition will be a much better choice, rather than installing the desktop edition and disabling all the desktop services that will be running by default and are only useful/usable on desktop systems.

The OP says he wants to use VNC to access the computer. From that, I conclude that he must have some GUI applications in mind. Come to think of it, does VNC (Remote Desktop) even work without a full-on desktop environment? I have a hard time picturing what it would look like.

Perhaps some clarification by the OP is in order: is it your intention to run any GUI applications on the headless host? If so, is it a small specific set, or do you want to run a generic suite of application software? A desktop environment?

--- rod.

It makes sense for us. Every headless Centos server here has both Gnome and KDE. With a remote X server, anyone on the LAN can connect to any Centos system, login and get a new instance of a desktop created.

Since we have some issues with remote X servers, anyone can also connect via ssh (which we also use for non GUI activities) and launch a new KDE or Gnome desktop inside a VNC server. Then one can connect and disconnect (without interrupting anything) to that desktop using a remote VNC client.

I have no idea what someone had to install/enable on those Centos systems to make all that available (I never did that step of a Centos install myself). But I don't think installing/enabling all of that is difficult.

Too trivial an amount to care about.

I can't tell from that statement whether you mean having a full desktop you might find convenient, saves time worth more than the space. Or installing a desktop you don't need costs your time (to install it), which bothers you more than the wasted disk space.

Regarding the original question: No one here ever installed Centos on a system without a temporary KVM connection. We have KVM switches allowing a few keyboard/monitor/mouse sets to be shared among a large number of Windows servers that each need KVM rarely. To set up a Centos, you borrow the KVM cables off a Windows system to go through one time first-install of Centos, then put the cables back because a Centos system typically never needs them again.

I just meant that spending a lot of time de-installing or taking special steps to make sure surplus packages didn't get installed isn't time well spent.

When you use a full D-E remotely, what sort of remote hosts are you using? Usually, a X-server host comes with a D-E already, and configured at a run-level where the D-E is present from boot-up.

--- rod.

I decided not to use VNC. I will stick only to ssh.

And if I decide to open some graphics, I will use the command "ssh -X"