More thinking about virtual machines...

[ryokimball]

Well, it's past 1:30 in the morning; I got out of bed to post this question (so please forgive me if I'm not entirely coherent). Anyways, I have been playing with the VirtualBox VM for many uses lately, and recent I began to wonder --why not have a virtual machine OS and be able to run multiple OSes from it? I mean, you get all the benefits of virtual machines without the limitations of the host OS, and I'd think that to be even better than dual-booting for those who can't get out of Windows for whatever reason. Oh, and it'd be really really really cool if it supported dual monitors, then you could have, say, Windows running on one monitor and Linux running on the other (or even better --dual Linux!); then you could use the same mouse and keyboard and just move between screens (no KVM switch) and be all fast and tidy and stuff....
Anyways, I looked around before asking any questions, and I've found a few that _might_ do what I'm thinking, but I'm really not sure. Here's the suspects (please tell me if you have any experience with them) :
Denali. Honestly, I just can't see exactly what this is; it's called an "operating system" but talks a lot about VMs, yet I don't see anything saying it can run linux or anything. Confused.
OKL4. Again, not much information. I think this is specifically for embedded systems, though... that said, would there be much point in running a VM on an embedded system?
Oracle VM A little more information on this one; for one, it seems more likely to do what I'm talking about, but according to Wikipedia's comparison sheet, it is very specific on which OSes it will run. Also unsure of licensing (well, I'm not completely sure on the licenses of the rest, for that matter).
Virtual Iron This sounds like a real winner, sporting around words like "native virtualization" and "hardware-assisted." But I'm pretty sure this one might cost mulah. I have no mulah.
VirtualLogix Embedded and licensing issues here.

Now...
If any of you have experience with these, that would be the first "awesome" I'd give you. If you can suggest something even better than what I've found at this late hour, that would be even awesome-er. (And feel free to talk loosely on the subject; I'm not really expecting to go very far with the idea).

Oh, and if you would like to, say, go in and develop and code a VM thingy that does everything I want and send it to me (email or CD or floppy or whatever), that would be Mega-Super-Ultra-Über Awesomely awesome. I might even pay you (but I have less than $5 in the bank...).

[HROAdmin26]

Of all of the virtualization apps you mentioned, I would call none of them "in the mainstream" (except for VirtualBox.)

In mainstream use by end users and/or enterprise, I would list:

VMWare ESX, ESXi, Server, Workstation (Enterprise and End User)
VirtualBox, QEMU, KVM (End User)
Xen (Enterprise and End User)
Parallels (Mac)
zVM, LPAR (Enterprise)

And from MSFT with Windows as the host OS - Virtual PC/Server and "Hyper-V." MSFT really hopes to make a dent in the virtualization market with Hyper-V since it's "free" with Windows 2008.

Some of these are free, some are not. Most of them have differing features/limitations.

As far as your post...This is what the "enterprise" apps do. They take over the hardware and run multiple VM server instances. This abstracts the VM from the hardware and (if done correctly) makes backup/recovery much quicker. VMWare ESX nodes in a cluster can move VM's from one node to another without dropping network connections (high availability.) Today's servers are coming with 24-128GB of RAM. It only makes sense to consolidate physical servers into VM's when each server (VM) only needs 1-4GB RAM. When your average laptop/desktop is coming with 4-8GB RAM, it can make sense there as well.

There are other threads on LF such as this and this.

[elija]

I am just starting to think about setting up a virtual box machine running CentOS (I believe that is a full RHEL) as a development web server.

I would like it to have a fixed IP and for my router to be able to use port forwarding to the virtual machine. Is that possible?

[ryokimball]

So, the "enterprise" versions can run straight off of hardware? My machine is no commerical server by any means; I have 4 GB ram and a fair dual-core AMD64 processor; I figure I could squeeze out two OSes fairly easily, though. If I found one of these "enterpise" versions, do you suppose that would still work?
And sorry for nearly cloning the other threads; at the late hour, I suppose such thoughts can be equated to brain-storming while hitting the bong --everything sounds ingenious and original (not that I'd know...). I looked over the other threads, though, and they don't seem so concerned about the core idea of mine --a hostless (more or less) VM.

[HROAdmin26]

...they don't seem so concerned about the core idea of mine --a hostless (more or less) VM.

If you take a look at the performance levels (and test them yourself as well), you see "near native" performance mentioned on quite a few. Given this, what would be the advantage to building very specialized HW for this purpose? (Which would *still* be a combination of HW and embedded software.) It would be costly to develop and ultimately, inflexible, when things change again (and they will.) Virtualization is nothing new and was heavily used when mainframes ruled the Corp datacenter.

So, the "enterprise" versions can run straight off of hardware?

Some of these are their "own OS" that is installed on the HW and some of them get installed into a host OS of your choosing or that they require. (LPAR's are specific to IBM HW, for example.)

Some of these are very thin "hypervisors" and have a very small footprint between the HW and VM. ESXi is the "embedded" version of ESX that runs from a very small linux install (32MB) or embedded memory.

You may want to consider the *reasons* for running different OS's in VM's. If you need access to more than one OS (whether it's for testing, learning, development, etc.), then VM's are great. Maybe you love Linux, but your school/work/hobby forces you to use a Windows-only app. No problem - install Windows in a VM and start it up when you need it. But for the average user with a simple desktop - I think it only makes their computer use more complicated. And we know how *that* goes...

If I found one of these "enterpise" versions, do you suppose that would still work?

In my use of the enterprise vs. end-user apps, I lean towards the end-user side for personal use. The ENT apps bring features to the table that typically mean nothing for personal use. They may also have steep HW requirements as well. Xen is up and coming...but I haven't found anything as fully-functional and consistent as VMWare Server, which supports (and is free):

Linux (every distro I've ever tried)
Windows (3.1 right thru 200
Solaris X86
NetWare
DOS
FreeBSD
and (unofficially) Mac OS X

I haven't seen any other match/eclipse that list. And with no BS limitations, like the no-remote-RDP limit in the free VirtualBox.

[questio verum]

<snip>
why not have a virtual machine OS and be able to run multiple OSes from it? I mean, you get all the benefits of virtual machines without the limitations of the host OS, and I'd think that to be even better than dual-booting for those who can't get out of Windows for whatever reason. Oh, and it'd be really really really cool if it supported dual monitors
<snip>

Dual monitor support aside, what you're describing sounds like a 'bare metal hypervisor'. Check the definition of 'type 1' hypervisor on this page and see if it sounds like what you're describing. Here's a chart of various hypervisors (vmm's) with a basic list of attributes. Check the 'Host OS(s)' column for bare metal candidates.

qv

[HROAdmin26]

Dual monitor support aside, what you're describing sounds like a 'bare metal hypervisor'. Check the definition of 'type 1' hypervisor on this page and see if it sounds like what you're describing. Here's a chart of various hypervisors (vmm's) with a basic list of attributes. Check the 'Host OS(s)' column for bare metal candidates.

qv

I took the question to mean something "above" Type 1 where the HW itself is ready for the guest OS install. But even this would be a combination of HW and a thin "firmware" (SW) layer...

As noted in QV's link:

A variation of this is embedding the hypervisor in the firmware of the platform