Re: txenmon: Cluster monitoring/management

[stevegt@TerraLuna.Org]

Though I didn't get a working xenolinux today, I did decide to try
today's tools with the 02 Feb 1.2 xen/xenolinux.  

- I like the new 'list' output.  Pretty!  ;-)

- After dealing with the builder_fn='xc.linux_build' vs.
  builder_fn='linux' change, I was able to suspend and restore a virtual
  domain just fine, including its swap VD.  I even ran my perl malloc
  torture test to make sure the swap device actually worked.

- Amusing note: I forgot to log off of the virtual domain before
  suspending it.  I thought about this after I resumed, thought "aww,
  gotta ssh in again", and then was in for a suprise.  The socket
  survived.  Very cool.  ;-)

- I'll go ahead and integrate the suspend/restore (should we just call
  this "resume"?) machinery into txenmon, so it can migrate guests
  between xenoservers without rebooting them.  I haven't tested restore
  to a different xenoserver yet, but am hoping that will just work.

G'night all,

Steve
 

On Tue, Feb 10, 2004 at 12:13:39PM -0800,  wrote:
> I see these save/restore updates in 'bk changes -R' -- my last pull was
> Monday a week ago.  And yes, using xc_dom_create.py for restore sounds
> like exactly the right idea; had just hit that realization myself late
> last night.
> 
> Pulling 1.2 at this instant; I'll exercise it and let you know how it
> goes.
> 
> Steve
> 
> On Tue, Feb 10, 2004 at 07:55:36PM -0000, Williamson, Mark A wrote:
> > > ...and a few other things.  Right now migration is via reboot, not
> > > suspend; haven't had a chance to troubleshoot resume further.  
> > 
> > We've improved the front-end to the resume functionality since you
> > highlighted the problenm, so you may want to have a look at the modified
> > tools if you have time.
> > 
> > The previous version xc_dom_control.py just called linux_restore in the
> > Xc library in order to reload a domain's memory state.  That didn't
> > recreate all of the VBDs, or set up the appropriate VFR (Virtual
> > Firewall Router) state, which was the problem you'd experienced.
> > 
> > I'm not sure what version of the tools you're using.  We now use
> > 'xc_dom_create.py' to start / restore domains - this can reads it's
> > configuration from a file, using the '-f' option.  We use
> > xc_dom_control.py to control running domains.
> > 
> > Using the latest tools stuff, you domains should be restored using
> > xc_dom_create.py, specifying the original configuration file as usual,
> > with the '-f' flag (which provides information for setting up the VFR /
> > VBDs again) but also the domain memory state file, using the '-L' flag
> > for 'Load domain state from file'.  That way, the VBD / VFR state gets
> > put back before the domain is restarted.
> > 
> > Also, the save option of xc_dom_control.py is now 'suspend' and it stops
> > and destroys the copy of the domain in memory after it has been
> > suspended to disk (so it can't change it's persistent storage, etc.,
> > which would otherwise confuse the image you if resume from file later).
> > 
> > > This is all to support a production Xen cluster rollout that I plan to
> > > have running by the end of this month.  I really don't want to go back
> > > to UML at this point, and if I don't have this cluster 
> > > running by March
> > > I'm in deep doo-doo -- so I'm committed to working full-time on Xen
> > > tools now.  ;-}
> > 
> > Thanks for the contribution!  And good luck, too!
> > 
> > Mark
> > 
> 
> -- 
> Stephen G. Traugott  (KG6HDQ)
> UNIX/Linux Infrastructure Architect, TerraLuna LLC
> stevegt@TerraLuna.Org 
> http://www.stevegt.com -- http://Infrastructures.Org 

-- 
Stephen G. Traugott  (KG6HDQ)
UNIX/Linux Infrastructure Architect, TerraLuna LLC
stevegt@TerraLuna.Org 
http://www.stevegt.com -- http://Infrastructures.Org 


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