Anyone Actually Using Virtual Linux Servers?

[Jarod Wilson]

On Sep 09, 2007, at 01:23, Kristian Erik Hermansen wrote:

> On 9/9/07, Jarod Wilson <jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org> wrote:
>> I frequently use kvm on my workstation when I need to spin up a
>> virtual machine. Its actually easier for me to deal with than vmware
>> (workstation, in this case), since everything is already in-kernel
>> and I tend to be running the latest and greatest upstream bits, so
>> the vmware-any-any patches don't always work...
>
> Yeah, kvm is great.  I use it occasionally, but I really need the
> VMware API for when I automate things.  If kvm has a nice user-level
> API, I am not aware of it (point me to docs?).

In Red Hat land, we've added support for kvm to libvirt, virt-install  
and virt-manager, so you can script up just about anything for kvm,  
so far as I know.

http://virt-manager.org/

> And kvm does of course
> require a CPU with the virtualization extensions, which makes it out
> of reach for many people's hardware.  My laptop, for instance, does
> not have these extensions.

True. Hell, my laptop can't even run Xen or VMware either...  
(PowerBook G4)

> Oh, hehe, yeah I forgot about the any-any patches.  You only need to
> use those if VMware is not packaged for your distro.  Luckily I run
> Ubuntu :-P

Actually, VMware *is* packaged for my distro (more or less), and I  
always install it from an rpm The issue is kernel-level support. If I  
were running an older kernel (like 2.6.22.x), it'd be no problem, but:

$ uname -r
2.6.23-0.164.rc5.fc8

(I'm a few days and git snaps behind now, I was out of town all week :)


>> Oh, and trust me, I know all too well just how fragile xen can be
>> without being very careful about what bits you're mixing -- a large
>> part of my day job these days includes working on ia64 xen. :)
>
> I think that Xen is fragile in many many ways, and that's why a lot of
> people are spending so much time debugging the problems with it.  As I
> said before, it is a very intrusive and non-ideal set of patches.
> When you start changing that much code, things are bound to get
> broken, especially when dealing with various architecture issues like
> 64-bits.  My personal opinion is that kvm will become the standard for
> the future.  Red Hat (you!) has a lot of engineers working on Xen.
> You might realize at some point in the future that kvm would free a
> lot of allocated resources :-)

Oh, many of us are already much more fond of kvm -- so many things,  
like frequency scaling, acpi, etc., Just Work, while they're not even  
close to functional under xen yet. Problem is, we've sorta kinda  
committed to supporting xen for the next 7 years with RHEL5, as well  
as providing a smooth upgrade path come RHEL6. My current favorite  
quote with respect to Xen Source's purchase by Citrix: "they (XS) got  
the gold mine, we (RH) got the shaft". So yeah, we've gotta keep  
working on xen. Don't be led to believe that means we're not doing a  
lot on the kvm front too though... (see earlier reference to libvirt,  
virt-manager, etc. :)

>> Out of curiosity, does HH include xen and/or does the prior LTS  
>> release?
>
> Yes, Ubuntu has included Xen since two releases ago.  I believe kvm
> was added officially in the last release, but don't quote me on that.
> I am running Ubuntu Gutsy at the moment.  I tend to run Ubuntu+1.
> Maybe now I will run Ubuntu+2, just for fun.  You seem to do the same.
>  Is there a Fedora 9 speclet yet, or will that happen after Fedora 8
> is released?

I believe the Fedora Project wiki contains some rough "things we'd  
like to do for F9" pages here and there, but it'll get more fleshed  
out after F8 goes into deep-freeze in about a month or so, iirc (my  
head has mostly been buried in the RHEL5 sand of late...)

-- 
Jarod Wilson
jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org