openstack team mailing list archive

[Thomas Goirand <thomas@xxxxxxxxxx>]

On 05/04/2011 05:07 PM, Jonathan Ludlam wrote:
> A shortlist of modified packages: LVM, biosdevname, dm-multipath,
> e2fsprogs, ethtool, open-iscsi, kexec. There are more, but these
> are the more important ones.

Gosh, I didn't know there was that much things involved, and frankly, I
don't understand why you had to modify that many things. It'd be great
if there was an effort to have everything upstreamed...

> The trouble is that XCP has been developed as an integrated
> system rather than an addon set of packages for an existing
> operating system. While it's not *far* off from being the
> latter, it would take quite a bit of effort both to figure
> out all the reason why each RPM has been patched

Especially for someone not part of the original team who built it, and
with so few information about XCP's internals on the web!

> not to mention
> all the implicit dependencies that we have on the behaviour of
> the underlying OS. We'd then have to figure out on a case-by-case
> basis whether the patch was general enough to upstream, and if
> not, whether a workaround existed that avoids the need of the
> patch, and if not, we'd have to patch the debs.

I strongly believe that the above is vital for XCP to continue to exist
in the long run. Sooner or later, you'll have a dependency hell trying
to upgrade to CentOS 6, or things like that.

> I think it could be made to work without *too* much effort so
> long as you were willing to sacrifice some bits of functionality.

I'm currently only interested in having the needed bits so that
Openstack can run with Xen, which I prefer over KVM. I've been told by
the people from RackSpace, that Openstack uses XCP for Xen. I'm not
interested to run CentOS at all (I'm a Debian Developer and work
exclusively with Debian), so my only option was to build the needed
things Openstack is using from XCP so that they run in Debian. I'm sure
other operating systems would have benefit from this work too.

I've added the openstack list to this thread, in the hope that someone
will be able to tell which bit from XCP is required by Openstack. If
there's not too much work involved, I'll go forward with my initial
idea, if not, I regret to say that I'll have to forget about Xen with
Openstack (unless using libvirt becomes an OK solution as well).

> I would guess that you could get an XCP system up and running on
> ubuntu within a couple of weeks or so, but it probably wouldn't
> be able to do LVM based storage backends, and I would guess a
> fair bit of the more advanced networking bits and pieces would
> require more effort.

FYI: I'm working on Debian packaging only (eg: not Ubuntu). I'm not sure
if Ubuntu guys will restart pulling Xen packages from SID (at some
point, Ubuntu dropped Xen support), but as dom0 support from kernel.org,
it's likely this will happen (as they will only need the Xen hypervisor
package from Debian). So if that happens, and I (with I hope, a bit of
your help) do the packaging work to have the needed XCP bits in Debian,
then we can reasonably hope to have Openstack to work flawlessly with
Xen and xapi, in both Debian and Ubuntu.

Hoping to get feedback from both Openstack and Citrix developers, so we
can see what can be done,
Cheers,

Thomas Goirand (zigo)