Chip, Previous releases of CloudStack may have set /proc/sys/xen/independent_wallclock in the cloud-early-config script which will properly sync clock for paravirtualized VMs. However, NTP is only solution that correct clock drift for both para and full virtualized VMs. Admittedly, I haven't looked in the history to see if this strategy was previously employed.
Thanks, -John On May 20, 2013, at 8:18 PM, Chip Childers <chip.child...@sungard.com> wrote: > On May 20, 2013, at 7:14 PM, John Burwell <jburw...@basho.com> wrote: > >> All, >> >> While it is tough to do, I must cast a -1 for the following reasons: >> >> Given that system VMs write files, this defect makes every file >> created/modified timestamp unreliable. >> Operational log correlation/debugging is nearly impossible since the clock >> is out of sync. >> It renders S3-backed Secondary Storage unreliable/useless >> >> As Ahmad pointed out, there are likely other instabilities/defects lurking >> due to this issue that we haven't discovered. >> >> I think we also need to determine whether or not this issue was introduced >> in 4.1. If not, we should consider back porting these fixes. > > It can't be this, because the system VM's for 4.1 are the exact same > images since 3.x releases. > >> >> Thanks, >> -John >> >> On May 20, 2013, at 5:29 PM, Ahmad Emneina <aemne...@gmail.com> wrote: >> >>> I'm +0 on this, dont want to hold up a release with a neg 1 vote. My >>> opinion is that time sync is critical piece for system vm's. Having the >>> wrong time can lead to system vm's booting and waiting for manual >>> intervention via consistency checks (potential blocker bug IMO). >>> >>> >>> On Mon, May 20, 2013 at 2:03 PM, Chiradeep Vittal < >>> chiradeep.vit...@citrix.com> wrote: >>> >>>> +1 >>>> >>>> On 5/20/13 1:15 PM, "Chip Childers" <chip.child...@sungard.com> wrote: >>>> >>>>> All, >>>>> >>>>> As discussed on another thread [1], we identified a bug >>>>> (CLOUDSTACK-2492) in the current 3.x system VMs, where the System VMs >>>>> are not configured to sync their time with either the host HV or an NTP >>>>> service. That bug affects the system VMs for all three primary HVs (KVM, >>>>> Xen and vSphere). Patches have been committed addressing vSphere and >>>>> KVM. It appears that a correction for Xen would require the re-build of >>>>> a system VM image and a full round of regression testing that image. >>>>> >>>>> Given that the discussion thread has not resulted in a consensus on this >>>>> issue, I unfortunately believe that the only path forward is to call for >>>>> a formal VOTE. >>>>> >>>>> Please respond with one of the following: >>>>> >>>>> +1: proceed with 4.1 without the Xen portion of CLOUDSTACK-2492 being >>>>> resolved >>>>> +0: don't care one way or the other >>>>> -1: do *not* proceed with any further 4.1 release candidates until >>>>> CLOUDSTACK-2492 has been fully resolved >>>>> >>>>> -chip >>>>> >>>>> [1] http://markmail.org/message/rw7vciq3r33biasb >>
