[Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Udo 'Robos' Puetz]

Hi List.
I'm in contact with one of the writers for the german (large) computer
magazine c't (computer and technology) defending qemu (he neglected some
features qemu has in one of his articles). Now he asks me for an article
about what the "average user" would benefit from when he would use qemu instead
of virtual pc/vmware (their "free" products, like player, ESX ...). The
examples I named up to now where
qemu -nographic -hda linux.img -kernel linux-2.6.17.6/arch/i386/boot/bzImage
-append "console=ttyS0
root=/dev/hda ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe" -hdb
fat:/mnt/data/Projekte/qemu/linux-test/bla
doing a little linux kernel driver development learning this way. (Good free 
pdf over at oreilly)
Also, when testing OCFS2 (Oracle cluster fs 2) and not having a SAN/iSCSI
system at hand I tried this:
qemu -hda breezy.img -hdb ocsf2.img
mounting that image once
qemu -hda breezy.img -hdb ocsf2.img
and now mounting it again in a second instance of qemu with slightly
different network setup. That works with qemu, vmware desktop wouldn't take 
the image a second time.
Also, a demonstration LiveCD could be made to boot on a system but also to
be played with qemu/qvm86 under win and linux (kqemu can't be re-distributed).
There would be statically built qemu's on the CD with bat/bash skripts to
start them (automatically).
Also, qemu can run happily on the server awaiting connects via vnc. But some
of the free products can do that too.

Soo, do you have any more ideas what qemu can what the (free) alternatives
from M$/VMWare can't?
Virtual PC can't handle USB _at_all_, what's the status of USB2.0 with qemu
( I think VMWare is still stuck on USB 1.1 )?
VMWare Desktop (not free) has "unlimited" snapshots IIRC, ESX just recently
got one snapshot functionality.

I can't say if I would do the article or the writer for the magazine but at
least it would make qemu more visible to (more technical inclined) people ->
good in my eyes.
Thanks for your suggestions
Cheers
Udo

-- 
Robos - 
gpg --recv-keys --keyserver blackhole.pca.dfn.de 6EEADA09

Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Oliver Gerlich]

Udo 'Robos' Puetz wrote:
> Hi List.
> I'm in contact with one of the writers for the german (large) computer
> magazine c't (computer and technology) defending qemu (he neglected some
> features qemu has in one of his articles). Now he asks me for an article
> about what the "average user" would benefit from when he would use qemu instead
> of virtual pc/vmware (their "free" products, like player, ESX ...). The
> examples I named up to now where
> qemu -nographic -hda linux.img -kernel linux-2.6.17.6/arch/i386/boot/bzImage
> -append "console=ttyS0
> root=/dev/hda ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe" -hdb
> fat:/mnt/data/Projekte/qemu/linux-test/bla
> doing a little linux kernel driver development learning this way. (Good free 
> pdf over at oreilly)
> Also, when testing OCFS2 (Oracle cluster fs 2) and not having a SAN/iSCSI
> system at hand I tried this:
> qemu -hda breezy.img -hdb ocsf2.img
> mounting that image once
> qemu -hda breezy.img -hdb ocsf2.img
> and now mounting it again in a second instance of qemu with slightly
> different network setup. That works with qemu, vmware desktop wouldn't take 
> the image a second time.
> Also, a demonstration LiveCD could be made to boot on a system but also to
> be played with qemu/qvm86 under win and linux (kqemu can't be re-distributed).
> There would be statically built qemu's on the CD with bat/bash skripts to
> start them (automatically).
> Also, qemu can run happily on the server awaiting connects via vnc. But some
> of the free products can do that too.
> 
> Soo, do you have any more ideas what qemu can what the (free) alternatives
> from M$/VMWare can't?
> Virtual PC can't handle USB _at_all_, what's the status of USB2.0 with qemu
> ( I think VMWare is still stuck on USB 1.1 )?
> VMWare Desktop (not free) has "unlimited" snapshots IIRC, ESX just recently
> got one snapshot functionality.
> 
> I can't say if I would do the article or the writer for the magazine but at
> least it would make qemu more visible to (more technical inclined) people ->
> good in my eyes.
> Thanks for your suggestions
> Cheers
> Udo
> 

Maybe qemu is not of so much use for the desktop user, but has its 
strength more in the direction of a generic "computer emulator" platform 
where other projects can build upon (see Argos or Free Live OS Zoo).
I'm not sure if Qemu really can compete with VMWare for a desktop 
virtualization software.

In my opinion the big advantage of Qemu is that it's open source. That 
makes it possible to use it as a basis for other projects; that also 
makes it possible to build the Live CD you mentioned. Another point is 
that an open source software is more likely to be shipped with Linux 
distros (OTOH VMPlayer is already available in some Ubuntu package 
repository, so this depends more on the distro maintainers). And if one 
wants to have a reliable platform to run legacy applications, an open 
source software has the advantage that you're not dependent on some 
company that might not exist in twenty years. Another point is the 
support of many host and guest platforms. But I think all this doesn't 
really help the desktop user.

What I think is quite nice is the USB tablet emulation. At least VMware 
requires that the VMWare tools are installed for mouse switching between 
host and guest. It's quite astounding that in Qemu this works (at least 
with Windows guest) without installing additional software.

So, IMHO you shouldn't try to praise Qemu as an end-user desktop 
virtualization software; presenting it to more technical users seems 
like a better idea.

Regards,
Oliver

Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Jan Marten Simons]

Udo 'Robos' Puetz wrote:
> Soo, do you have any more ideas what qemu can what the (free) alternatives
> from M$/VMWare can't?
>   
Qemu can be used without the need to install anything, which is
especially useful if you put a preconfigured OS image plus qemu 
binaries (for different host OS') and startup scripts on a dvd.
Additionally it's very nice in this context, that qemu does not need
admin/root priviledges.

hth,
Jan

Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Linas Žvirblis]

Oliver Gerlich wrote:

> So, IMHO you shouldn't try to praise Qemu as an end-user desktop
> virtualization software; presenting it to more technical users seems
> like a better idea.

Not necessarily. It is true that QEMU offers a load of features that
technical users will enjoy, but also various desktop user-oriented
projects use it as an engine for their products. These include GUI
front-ends, various extensions for popular desktop environments, etc.
This effectively makes QEMU *the* emulator for the Free software community.

Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[andrzej zaborowski]

> Soo, do you have any more ideas what qemu can what the (free) alternatives
> from M$/VMWare can't?

I must admit I haven't used Virtual PC and have no idea about what it
can do, but I tried VMWare.

In terms of using, apart from the source code, I think the biggest
advantage of QEMU is the amount of hardware it can emulate. There's a
number of input devices, graphics cards, NICs, storage devices and
above all CPUs. VMWare can do only a very little part of this, and it
doesn't emulate the CPU at all, it only virtualises it. It won't run
on a platform different than i386 or with a guest different than i386.

So, QEMU is a quite generic computer emulator and I don't know if the
word "alternatives" can be used because they don't have the
functionality that I personally exploit in QEMU.

Also, if I was forced to use VMWare for some reason, I would miss the
flexibility of -monitor, -serial, and the options related to the
graphics display, as well as the debug info I can get from QEMU.

Regards,
-- 
balrog 2oo6

Dear Outlook users: Please remove me from your address books
http://www.newsforge.com/article.pl?sid=03/08/21/143258

Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Kevin F. Quinn]

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On Fri, 28 Jul 2006 15:58:06 +0200
Udo 'Robos' Puetz <udo@muon.de> wrote:

> Soo, do you have any more ideas what qemu can what the (free)
> alternatives from M$/VMWare can't?

Well, in addition to system emulation qemu that I'd guess most users
want qemu for, it has "user" emulation where you can run for xample an
ARM binary on an x86 host. It also emulates many targets, not just the
x86/x86_64 that VMware or VirtualPC support - bear in mind these are
virtualisation tools, not emulators, where as qemu is primarily an
emulator with virtualisation acceleration for native x86/x86_64 targets.
This makes qemu great for cross-target development. See
www.scratchbox.org for example.

Obviously qemu also has the advantage that (apart from the virualisation
module kqemu) it's open source, which means a lot to many people,
at least for me!

-- 
Kevin F. Quinn

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Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Udo 'Robos' Puetz]

On Fri, 28.07.06, Udo 'Robos' Puetz <udo@muon.de> wrote:
Hi List.

I'll write this here instead of answering to each to keep the noise down :)
Thanks a lot for the good ideas and comments!
I'll simply collect the ideas and leave my cynical comments about lazy readers
of computer magazines to myself :) (Everybody sees that qemu is waaay better
than the others, why do they need to be shown? ;-)
-run kernel by itself
-user emulation (putty example in docs)
-OSS -> independant of a company becoming bankrupt
-free distributable
      -put on a live cd
      -put in a distro
-can be used without the need to install anything
-qemu does not need admin/root priviledges
-usb tablet emulation -> no need to install vmware tools in client
-can record audio (and with patch even mpegs)

Thanks again for your input!
Cheers
Udo

-- 
Robos - 
gpg --recv-keys --keyserver blackhole.pca.dfn.de 6EEADA09

Re: [Qemu-devel] What can qemu do that vmware/virtual pc can't...article idea

[Bill C. Riemers]

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It seems to me you missed the most important qemu feature.  That is qemu
will emulate different processors.  Just try running an PPC version of Linux
on an x86 with VMWARE.  To my knowledge the only other programs that can do
this are either very expensive or extremely slow.

Bill


On 7/28/06, Udo 'Robos' Puetz <udo@muon.de> wrote:
>
> Hi List.
> I'm in contact with one of the writers for the german (large) computer
> magazine c't (computer and technology) defending qemu (he neglected some
> features qemu has in one of his articles). Now he asks me for an article
> about what the "average user" would benefit from when he would use qemu
> instead
> of virtual pc/vmware (their "free" products, like player, ESX ...). The
> examples I named up to now where
> qemu -nographic -hda linux.img -kernel linux-2.6.17.6
> /arch/i386/boot/bzImage
> -append "console=ttyS0
> root=/dev/hda ide2=noprobe ide3=noprobe ide4=noprobe ide5=noprobe" -hdb
> fat:/mnt/data/Projekte/qemu/linux-test/bla
> doing a little linux kernel driver development learning this way. (Good
> free
> pdf over at oreilly)
> Also, when testing OCFS2 (Oracle cluster fs 2) and not having a SAN/iSCSI
> system at hand I tried this:
> qemu -hda breezy.img -hdb ocsf2.img
> mounting that image once
> qemu -hda breezy.img -hdb ocsf2.img
> and now mounting it again in a second instance of qemu with slightly
> different network setup. That works with qemu, vmware desktop wouldn't
> take
> the image a second time.
> Also, a demonstration LiveCD could be made to boot on a system but also to
> be played with qemu/qvm86 under win and linux (kqemu can't be
> re-distributed).
> There would be statically built qemu's on the CD with bat/bash skripts to
> start them (automatically).
> Also, qemu can run happily on the server awaiting connects via vnc. But
> some
> of the free products can do that too.
>
> Soo, do you have any more ideas what qemu can what the (free) alternatives
> from M$/VMWare can't?
> Virtual PC can't handle USB _at_all_, what's the status of USB2.0 with
> qemu
> ( I think VMWare is still stuck on USB 1.1 )?
> VMWare Desktop (not free) has "unlimited" snapshots IIRC, ESX just
> recently
> got one snapshot functionality.
>
> I can't say if I would do the article or the writer for the magazine but
> at
> least it would make qemu more visible to (more technical inclined) people
> ->
> good in my eyes.
> Thanks for your suggestions
> Cheers
> Udo
>
> --
> Robos -
> gpg --recv-keys --keyserver blackhole.pca.dfn.de 6EEADA09
>
>
>
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel
>

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