Re: [Xen-devel] bi-directional console / live migration & kernel 2.6

[Ian P. <Ian...@cl...>]

> On the Website I read, that bi-directional-console is "complete", live migration feature (wow!)
> is "nearly complete" 

Both bi-directional console and live migration are in the default
build of the 'unstable.bk' tree on bitkeeper. We hope to release
this as 2.0 in roughly 6-8 weeks time.

Stability of the unstable tree is actually pretty good (modulo
the scheduler tweak that got backed out yesterday).

> and a Port to 2.6 Kernel is "nearly complete", too.

Christian Limpach has done some great work to get 2.6
running. We're trying to make this port as clean as possible with
the intention of trying to get arch-xen included in the
mainstream Linux tree.

> Can you give me a pointer, were to read more about that or when/how the "public" is able to try/test 
> this ? 

Just download and build xeno-unstable.bk or use one of the
nightly pre-built versions available from the downloads page on
the website. 

The README/CD file in the new tree contains some docs (e.g. you
need to run "xend start" in dom0 before starting other domains)
but that's an area we're very thin on and would appreciate help.

As regards live migration, just do a suspend/resume to a 'file'
called "tcp://<remote_hostname>:<port> and you'll get live
migration[*]. Depending on what the domain is doing, the downtime of
the domain can be just a few milliseconds, even for a 1GB domain.
The script currently uses an unsolicited broadcast ARP reply to
tell other hosts on the network that the VM has migrated to a new
MAC address. You could in principle migrate the MAC too.

I'm still doing a few tweaks to some of the heuristics in the
live migration algorithm, and the output is currently very
verbose, but it seems to work well even for domains running
complex system benchmarks like OSDB/Postgres and
SPECweb99/Apache. It would be useful to start getting feedback
from others, at least after the end of the week.

Ian

[*] The current tools are a bit confusing in this regard: use
the -L option to "xc_dom_create" for resume, and "xc_dom_control suspend"
for suspend. You'll need to start the "resumer" before doing the
suspend if you're doing a migration.