From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guillaume Rousse Subject: Re: comprehensive documentation of clock-related options for HVM guests Date: Tue, 17 Feb 2009 09:38:44 +0100 Message-ID: <499A7794.1050503@inria.fr> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com Cc: dan.magenheimer@oracle.com, "xen-devel@lists.xensource.com" , keir.fraser@eu.citrix.com List-Id: xen-devel@lists.xenproject.org Keir Fraser a =E9crit : > It's also worth pointing out that NTP synchronisation in dom0 does not > affect HVM guest synchronisation at all. And in general that would be v= ery > hard to do in a way that isn't fragile. The only solutions I can see he= re > for absolute time synchronisation are a PV driver or daemon for time > handling (which we do not currently have for any type of HVM guest) or > perform NTP synchronisation in the guest itself (our time handling shou= ld be > accurate enough for an ntp daemon to latch onto it). That's what (ntp sync in guests) we do, sorry if I wasn't clear. I've=20 tried timer_mode=3D1 yesterday, it seem to have reduced the deviation to=20 an acceptable level for every host but one. I'll try to switch to=20 timer_mode=3D2 today. --=20 BOFH excuse #40: not enough memory, go get system upgrade