Can anyone recommend a Virtual Machine that doesn't require X that I could consolidate my servers onto?

I'm playing with VirtualBox but it seems to need a GUI.

Have you tried KVM yet?

Qemu has a decent -curses switch that works well.

Another vote for qemu.

You can start a VM without a GUI running it as a VNC server.
You can then connect from any box on the network to see the "screen" of your VM.

I have been using this setup successfully for a while now.

Virtualbox does not need a GUI. I use Virtualbox headless all the time. Check out the "VBoxHeadless" and "VBoxManage" commands. There was a recent article on howtoforge, IIRC, about this as well.

Edit: Here is the howtoforge article:

http://howtoforge.com/vboxheadless-r...tos-5.4-server

The article was written with CentOS in mind, but the VirtualBox commands the author goes through of course would work on any distro including Slackware.

So, which typically runs faster, VirtualBox, Qemu or KVM?

(I'm running apache, mail and fileserving with samba...)

Please note that Qemu is the userspace part of the KVM package; and I believe Qemu technology can be found in VBox as well.

I can't vouch for VBox but I can tell you I can have up to 15-20 users accessing a Debian Samba server running a KVM Windows 2003 terminal services VM and they don't suspect a damn thing. Speed is blinding; and I haven't had that server blink on me once in two and a half years.

Not once.

It was my first VM setup and pretty much my first serious Linux server. KVM won't let you down. I run my own VMs here and I can have three or four Linux/BSD/MS virtual machines open at a time. Speed is native. The only thing I hear people complain about regarding KVM is its relatively poor graphics performance but on a server with no X that's not going to affect you.

If I were setting up that server now I would use Slackware and KVM without hesitation. There is a Slackbuild for KVM/Qemu.

I compiled packages for VirtualBox and then decided to give KVM a try based on you guys but, I've hit a snag.

My test box is old and does not have BIOS Virtualization. Does anyone have instructions/a link to how to set up QEMU/KVM on boxes without BIOS Virtualization? I was reading through the QEMU wiki and apparently, it will run without the virtualization.

BTW, I'm running 32bit Slack 13 on this machine.

There is nothing special during install. When running, you can use the "-curses" option to let qemu use character terminal (instead of graphics window) as display output.

QEMU can run without virtualization support, but it will run a lot slower. You better try QEMU with KQEMU kernel module.

KVM, on the other hand, *requires* virtualization support (either Intel-VT or AMD-V).

Unfortunately KQEMU is obsolete:

http://wiki.qemu.org/Manual

I'm not even sure it still works with the latest QEMU.

KQemu is still available on slackbuilds.org. I will try to keep it there as long as I can (I'm the maintainer). But it does work with Qemu on 13.0 right now. Not sure yet how it will behave on 13.1.

http://slackbuilds.org/repository/13.0/system/kqemu/
http://slackbuilds.org/repository/13.0/system/qemu/

I will probably put the build scripts for Qemu + KQemu on my personal site if Qemu is updated and no longer works with the latest Qemu.

SOOOooooo, I have to have BIOS Virtualization to get KVM to work?

The short answer is yes. KVM requires BIOS virtulization. KVM will fallback to just QEMU mode if BIOS virtulization is available but the KVM modules are not loaded. QEMU emulation alone is slow without either software acceleration (KQEMU) or hardware (AMD-V or Intel VT) acceleration.