From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Fitzhardinge Subject: Re: Re: XenParavirtOps wiki page updates Date: Fri, 19 Dec 2008 12:53:21 -0800 Message-ID: <494C09C1.5070009@goop.org> References: <1e16a9ed0812131133p522eed2fhb54e6e8c5192b360@mail.gmail.com> <87fxkpveit.fsf@tac.ki.iif.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87fxkpveit.fsf@tac.ki.iif.hu> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ferenc Wagner Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Ferenc Wagner wrote: > Thanks for collecting this very useful bunch of information! > Here is what I still miss: > > * Features in 2.6.26: > Balloon (contraction only) > > It isn't clear whether this contraction is reversible or not. > It is, but only up to the original size. > * If the domain crashes very early, before any output appears on the > console, then booting with: should provide some useful information. > > Booting with what? > earlyprintk=xen > * How to achieve time sync between the dom0 and the domUs? Lots of > people seem to have problem with domU clock drift, me included. > Ntp doesn't work in domU, and apparently no clocksource guarantees > such synchronization. > Why doesn't ntp work? As far as I know it should. The 2.6.18-xen kernels have a mechanism to try and sync the domains to the hypervisor's time, but it doesn't fit well into the current kernel's timekeeping. I think either ntp or a lightweight daemon should be able to do this from usermode. (I was thinking of adding some /sys files to publish the hypervisor's current time, which a daemon could use to warp the domain's time to match.) > * I couldn't find it documented anywhere that SysRq is available via > Ctrl+O on the domU and more importantly on the dom0 serial console. > > * The idle count doubling I still experience happens with pvops > guests only (http://lkml.org/lkml/2008/9/18/276). > That is pretty strange. > Otherwise, Debian's pvops guest kernel works very good for me, already > in production. > Good to hear. 32 or 64 bit? J