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From Chiradeep Vittal <Chiradeep.Vit...@citrix.com>
Subject Re: [VOTE] Move forward with 4.1 without a Xen-specific fix for CLOUDSTACK-2492?
Date Tue, 21 May 2013 00:31:11 GMT
No, they couldn't have set that since this flag is not available on Debian
2.6.32

On 5/20/13 5:26 PM, "John Burwell" <jburwell@basho.com> wrote:

>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.childers@sungard.com>
>wrote:
>
>> On May 20, 2013, at 7:14 PM, John Burwell <jburwell@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 <aemneina@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.Vittal@citrix.com> wrote:
>>>> 
>>>>> +1
>>>>> 
>>>>> On 5/20/13 1:15 PM, "Chip Childers" <chip.childers@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
>>> 
>


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