Re: Re: [Xen-users] Blktap in mainline kernel 3.x

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Nov 02, 2011 at 12:57:04PM -0400, David Della Vecchia wrote:
> I've had it running for about a month now with no issues, i've got 35 beta
> tester domU's on the box and everything seems to be going swimmingly.
> 
> A few things to keep in mind:
> 
> For some reason the debian xen packages do not have pv-grub so you need to
> acquire that elsewhere, it doesn't need to be built on your system though,
> i downloaded mine from a forum post somewhere (i used to download the xen
> source and compile from scratch to get it).
> This next one isn't so much a dom0 problem as a domU one but for some
> reason debian squeeze (stable) guests are not capable of saving and
> restoring their state. On restore the console and/or network devices will


That is the 2.6.32 kernel? Yeah, there are couple of bug-fixes floating
around for that. Ian might know exactly which ones.

> be locked/frozen. I was able to get it to kinda work by custom compiling a
> 3.0.4 kernel but even then it was not reliable; however the centos domU's
> are able to save/restore flawlessly. This was all on the wheezy dom0.
> 
> The xen packages in debian, and this might be the default for xen4.1+ now,
> expect you to setup your own bridge, the network-bridge line of the
> xend-config.sxp will be commented out or just not there at all. I put it
> back in, I let the script the handle the bridging since it works fine for
> my needs; that and my attempts to manually create a bridge following the
> xen instructions always fail for some reason.
> 
> Stuff gets put into /usr/lib/xen-4.1 instead of /usr/lib/xen so i had to
> update a lot of my scripts and config files when i switched to debian.
> 
> Also as far as i can tell, wheezy uses the stock 3.0.0-1 kernel for xen so
> no custom kernel required like in squeeze with its 2.6.32-5-xen (its my
> understanding this is the pvops option?).

<nods>
> 
> As far as hvm guests go, as long as you use the hvmloader from the package
> you'll be fine, if you custom compile xen there's a good chance your
> hvmloader will be corrupted, it has something to do with the newer version
> of gcc, though this may have been fixed in 4.1.2.

Yeah, it was something about __main being placed in the wrong offset.
I *hope* that has been fixed in 4.1.2.