VMware vs. VirtualBox vs. ...

On Mon, 19 Jan 2009 11:56:14 -0500, Adam wrote:

> I've seen numerous posts lately about problems with VirtualBox, but I
> don't recall any posts about VMware.

If in this news group, most have been growing pains on a VirtualBox New Release.
Currently there is an open bug report about guest display not working well
with 2009.1 Alpha 1.

Saw a post where VMware allocates memory as the guest needs it whereas VB
takes what you allocated for the guest during guest launch.

On Monday 19 January 2009 17:56, someone identifying as *Adam* wrote
in /alt.os.linux.mandriva:/

> [...] Are there other options? I'm interested in running both Windows and
> other Linux distros under it, whichever it is. [...]

If your hardware supports virtualization - i.e. Intel VT (formerly
Vanderpool) or AMD SVM (formerly Pacifica) - then Xen might be an
interesting option for you.

Unlike VMWare or VirtualBox, Xen doesn't run your "guest" virtual machine on
top of the operating system, but instead runs every operating system
instance as an isolated virtual machine, including the "host" operating
system.

Xen is a hypervisor that gets booted the same way you would normally boot a
kernel, but with a modified Linux, NetBSD or OpenSolaris "host" kernel as a
module to the hypervisor. This will thus boot the "host" operating system,
from which you then manually or automatically boot the "guests".

Xen has two virtualization methods. The first one is called
paravirtualization (PVM) and works on hardware which doesn't have any
virtualization extensions. It requires that the "guest" kernel be patched
for use in a paravirtualized environment, in which case the "guest" kernel
will access the hardware using backend drivers in the "host" kernel. You
cannot use this kind of virtualization with Microsoft Windows because of
the proprietary nature of that (attempt at an) operating system.

The other virtualization method is hardware virtualization (HVM) and as the
name suggests, it requires that the hardware has virtualization extensions
- which is the case on all Intel Core 2 and AMD 2nd generation /x86-64/
platforms. Hardware virtualization does not require any modification of
the "guest" operating system. Each operating system has access to
processor rings 0 to 3, and the "host" will run in the processor's root
mode, while "guests" run in non-root mode. This means that any attempts to
directly access the hardware from within the "guest" will be trapped by the
hypervisor as so-called /hypercalls./

In comparison to VirtualBox or VMWare, Xen makes your computer act and feel
more like a mainframe would. You manipulate the virtual machine instances
from within the "host" system, but they all run side by side, and not "on
top of" the "host" system.

Xen exists both as FOSS and as a commercial product. You can download the
free version - either as binaries or as sources - from...

http://www.xen.org

.... or possibly as a Mandriva package. (Open)SuSE and RH/CentOS/Fedora
offer Xen and XenLinux host, guest and unified[1] kernels, so I'd be
surprised if Mandriva didn't.

Xen supplies 2.6.18 kernels for both the host and the paravirtualized
guests, but other distributions have patched more recent kernels, i.e.
2.6.20 from RedHat and 2.6.22 from Ubuntu. Later Linux kernels cannot be
patched because Linus has included paravirtual guest support in the
official kernel tree as of 2.6.23, which is adapted for use with more
virtualization solutions than just Xen - notably with KVM (kernel-based
virtual machine) and the somewhat similar but very lightweight /lguest/ -
and which therefore is quite different from and somewhat less functional[2]
than the Xen-specific paravirtualized guests. These patches also make it
very difficult to use Linux versions from 2.6.23 on as Xen hosts.


*[1]* In Xen, the host system is called "domain 0" or /dom0/ and the guests
are called "domain U" or /domU./ A /dom0/ kernel has backend drivers, and
a paravirtualized /domU/ kernel has frontend drivers that connect
to /dom0's/ backend drivers. Hardware-virtualized guests are installed "as
they are" and need not be modified. A unified kernel also exists, which
can be used both as a host and as a paravirtualized guest, but the unified
kernel is a lot larger than a paravirtualized /domU/ kernel.

*[2]* Certain things like PCI pass-through - which allows a /domU/ virtual
machine to directly access a hardware device that was isolated from the
hypervisor and from the /dom0/ kernel at machine boot time - may not work
if post-2.6.22 kernels are used as guests, and - although this may have
been resolved in the meantime[3] - 2.6.23 and later kernels may not work in
64-bit long mode and/or with SMP support.

*[3]* Last time I've checked a kernel Changelog, this issue was still a work
in progress due to the merging of the previously separate source trees for
32-bit and 64-bit systems. It was expected that the merger would enable
post-2.6.22 vanilla kernels to run as 64-bit paravirtualized guests and
with symmetric multiprocessing support, but I have not checked on any of
the progress since as I've decided to stick with 2.6.22.

--
*Aragorn*
(registered GNU/Linux user #223157)

On Mon, 19 Jan 2009 11:56:14 -0500, someone posting as Adam purportedly
wrote:

> I've seen numerous posts lately about problems with VirtualBox, but I
> don't recall any posts about VMware. Which do you prefer? Are there
> other options? I'm interested in running both Windows and other Linux
> distros under it, whichever it is. Thanks in advance!

I've used both. Paid for VMWare since v.3. It did what I needed it to
do. I've used VirtualBOx for a year now. Quite impressive. Only snag
so far has been with Slack12.2...but I'll get that sorted out soon enough.


--
shut up and run.

On Mon, 19 Jan 2009 11:56:14 -0500, Adam <adam@address.invalid> wrote:

> I've seen numerous posts lately about problems with VirtualBox, but I
> don't recall any posts about VMware. Which do you prefer? Are there
> other options? I'm interested in running both Windows and other Linux
> distros under it, whichever it is. Thanks in advance!

There are probably more posts about problems with VirtualBox, because there
are more people using it.

I found the setup of VirtualBox to be much more intuitive, than VMWare. I
currently have xp-pro, windows 7 beta, and Mandriva 2009.1 alpha clients
that I run under VirtualBox, from either a Mandriva 2009.0 host, or a
2009.1 alpha host.

I originally installed the 2009.1 alpha under VirtualBox, then used nfs
running on the 2009.0 host, to access filesystems on the host, where I
then cloned the 2009.1 alpha system.

Regards, Dave Hodgins

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On Mon, 19 Jan 2009 13:04:02 -0500, Jim Beard <jdbeard@patriot.net>
wrote:

>Adam wrote:

>> I've seen numerous posts lately about problems with VirtualBox, but I
>> don't recall any posts about VMware. Which do you prefer? Are there
>> other options? I'm interested in running both Windows and other Linux
>> distros under it, whichever it is. Thanks in advance!

>
>Those who have been running virtual machines for several years
>seem to credit VMWare with greater capabilities and greater ease
>for some purposes, such as moving virtual machines around.
>They seem to believe that NAT used by VirtualBox is fine for
>ordinary users, but when NAT is not adequate VirtualBox is a
>pain to configure properly for network communications.
>
>Bear in mind that these guys are paying customers (or at least
>the Defense Department is paying). There are restrictions on
>what you can do under VMWare without paying for the privilege,
>and that might make a difference.
>
>With VirtualBox, all is free, with some restrictions/reduced
>capability if you choose the Open Source version rather than
>the Sun proprietary version.
>
>Cheers!
>
>jim b.

Actually VMWare server is available as a free download from
VNWare and there are no restrictions to it.

Robert

Thanks for all your useful comments, Jim and Bit Twister and Aragorn and
wordsmith and Dave and Robert!

Aragorn, I'm surprised I didn't think of Xen since the local LUG
founder/president was one of the developers and talked about it a lot.

Dave, it sounds like you're using virtual machines for pretty much the
same purposes that I would.

I asked this question at the last LUG meeting, and there wasn't much
discussion -- they said that VMware is a pain to run, but VirtualBox
crashes so it's even worse.

After considering everyone's comments, I conclude... I dunno. I guess
I'll just have to try both and make my own decision, now that I have the
HD space. :-) Thanks again, everyone!

Adam

On Mon, 19 Jan 2009 20:29:54 -0500, Adam <adam@address.invalid> wrote:

> discussion -- they said that VMware is a pain to run, but VirtualBox
> crashes so it's even worse.

The most recent update was a bit of a pain to install, as it required
actually reading the docs, on changes to how the host interface networking
works. After a simple change to the configuration to refeclt those changes,
it's been working flawlessly.

The only problem with Mandriva 2009.1 alpha, is that the x11/kernel module for
the vboxmouse and vboxvideo was not updated with the latest x11 update, so
x11 has to be run in vesa mode.

With windows 7 beta, it can't handle any of my usb devices, when run as a
virtualbox client. Don't know if it can, if I were to install it as a host.

I've had no problems with virtualbox crashing.

Regards, Dave Hodgins

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David W. Hodgins wrote:

> On Mon, 19 Jan 2009 20:29:54 -0500, Adam <adam@address.invalid> wrote:
>

>> discussion -- they said that VMware is a pain to run, but VirtualBox
>> crashes so it's even worse.

>
> The most recent update was a bit of a pain to install, as it required
> actually reading the docs, on changes to how the host interface networking
> works. After a simple change to the configuration to refeclt those changes,
> it's been working flawlessly.
>
> The only problem with Mandriva 2009.1 alpha, is that the x11/kernel module for
> the vboxmouse and vboxvideo was not updated with the latest x11 update, so
> x11 has to be run in vesa mode.
>
> With windows 7 beta, it can't handle any of my usb devices, when run as a
> virtualbox client. Don't know if it can, if I were to install it as a host.
>
> I've had no problems with virtualbox crashing.
>
> Regards, Dave Hodgins
>

Well - the latest virtualbox has another problem. You cannot
activate pass-trough without losing the CD/DVD drive in the
guest. So it is not possible to use any burning CD/DVD
software from the guest, because the CD/DVD drive is seen as
read-only.

A friend of my uses virtualbox only for Nero Vision and
Publisher. Both of them do not run on wine, so there is no
other way to use this programs. He had to revert back to
version 2.0.6 because of this problem.

If someone has the same problem it is good to know it has
nothing to do with Mandriva 2009.1 alpha, but with
virtualbox version 2.1 itself.

John.