Ilya and Chip, I stand duly corrected. Sorry for diverting the conversation.
-John On May 30, 2013, at 2:22 PM, "Musayev, Ilya" <imusa...@webmd.net> wrote: > I forgot to mention, with option 1, you should have the least issues > regardless of what hypervisor technology you use - even if you go with HyperV > :) > > And I think Chiradeep is right, it should be Zone based, since this is when > SSVM and CPVM gets created. > >> -----Original Message----- >> From: Musayev, Ilya [mailto:imusa...@webmd.net] >> Sent: Thursday, May 30, 2013 2:14 PM >> To: dev@cloudstack.apache.org >> Subject: RE: [DISCUSS] How to best do time sync. (WAS: [VOTE] Release >> Apache CloudStack 4.1.0 (fifth round)) >> >> John, >> >> For vmware, you have 2 options, clock sync will work with native NTP >> daemon using local ntp servers in your datacenter or use vmware tools >> native time keeping technique. >> >> We have over 2500 VMs, and while we have vmware tools installed on all >> vms, we choose to use native linux NTPD for time sync VS vmware >> hypervisor provided time sync. In past, vmware tools time sync was buggy >> and not recommended, so we decided to keep it simple and make use of >> existing ntp servers. As of now, inherent issues maybe, if you go through >> major upgrade of Vsphere, if you change vmware hardware version, if you >> don't update the tools - you have 3 places where time keeping may break >> (though I hope vmware dev team consider all that - it is still a possibility) >> >> I propose we make this optional when cluster is configured. >> >> For example, we have a check box that says >> 1) use local NTP servers for time keeping (if selected) >> NTP SERVER1 >> NTP SERVER2 >> 2) use native hypervisor vm tools for time sync (be it vmware,kvm, xen or >> whatever else it may be) >> >> We let user make his own decision on how to go about this issue, and user >> would know best what's applicable for his environment VS us, making >> decisions on their behalf. >> >> For vmware, we have have to submit 3 more arguments into "vm.details" >> attribute with an option for timesync=vmtools ot timesync=ntp >> If timesync=ntp, get values of ntpserver1 and ntpserver2, configure >> local ntp.conf file to use with native linux ntpd daemon >> If timesync=tools, use vm tools provided time keeping technique >> >> Feedback is welcome, >> >> Thanks >> -ilya >> >> >>> -----Original Message----- >>> From: John Burwell [mailto:jburw...@basho.com] >>> Sent: Thursday, May 30, 2013 1:44 PM >>> To: dev@cloudstack.apache.org >>> Subject: Re: [DISCUSS] How to best do time sync. (WAS: [VOTE] Release >>> Apache CloudStack 4.1.0 (fifth round)) >>> >>> IIya, >>> >>> I can't speak to KVM, but on VMWare, clock sync won't work without tools. >>> It's not an option. >>> >>> Thanks, >>> -John >>> >>> >>> On Thu, May 30, 2013 at 1:30 PM, Musayev, Ilya <imusa...@webmd.net> >>> wrote: >>> >>>> I'd say Cluster setting. >>>> >>>> We should let users pick if they want to use hypervisor tools based >>>> sync or local/external NTP servers. >>>> >>>> I'm all for local/external NTP servers, as I know how those never >>>> gave me issues in past (especially when you go through hypervisors >>>> upgrades and vm tools upgrades). >>>> >>>> >>>> >>>>> -----Original Message----- >>>>> From: John Burwell [mailto:jburw...@basho.com] >>>>> Sent: Thursday, May 30, 2013 1:02 PM >>>>> To: dev@cloudstack.apache.org >>>>> Subject: Re: [DISCUSS] How to best do time sync. (WAS: [VOTE] >>>>> Release Apache CloudStack 4.1.0 (fifth round)) >>>>> >>>>> Ilya, >>>>> >>>>> One very important note is that NTP is only used for Xen. For KVM >>>>> and VMWare, time sync is accomplished through kernel >>>>> drivers/system daemons with NTP configured in the hypervisor >> configuration. >>>>> Therefore, this >>>> model >>>>> would need to be conditional based on the hypervisor type -- >>>>> possibly a cluster-level setting? >>>>> >>>>> Thanks, >>>>> -John >>>>> >>>>> On May 30, 2013, at 12:58 PM, "Musayev, Ilya" >> <imusa...@webmd.net> >>>>> wrote: >>>>> >>>>>> Thanks Chip. >>>>>> >>>>>> I've posted this response under CLOUDSTACK-2492.. curious what >>>>>> others >>>>> may think about a long term solution to this problem.. >>>>>> >>>>>> -------------- >>>>>> I think we should make the whole NTP schema more modular and >>> robust. >>>>>> >>>>>> For example, in my experience working for several companies, not >>>>>> even once have we used vmware tools time sync - due to known >>>>>> bugs and issues. Instead we would prefer to use local NTP server >>>>>> or external pool.ntp.org >>>>>> >>>>>> There are two way we can address this: >>>>>> >>>>>> Quick solution (quick means not ideal): >>>>>> Capture the NTP servers defined on MS and feed it as arguments >>>>>> to system vms On initial start of the system vm, check if you >>>>>> can access ntp servers defined on MS vm, if not, check if you >>>>>> can access pool.ntp.org servers - if none defined - use >>>>>> hypervisor tools sync >>>>>> >>>>>> Long term solution: >>>>>> When adding zones, define NTP servers in UI to be used with >>>>>> system VMs >>>>> or bypass NTP servers and allow vm-tools time sync with hypervisor. >>>>>> >>>>>> Thoughts? >>>>>> >>>>>> Thanks >>>>>> ilya >>>>>> >>>>>>> -----Original Message----- >>>>>>> From: Chip Childers [mailto:chip.child...@sungard.com] >>>>>>> Sent: Wednesday, May 29, 2013 2:30 PM >>>>>>> To: dev@cloudstack.apache.org >>>>>>> Subject: [DISCUSS] How to best do time sync. (WAS: [VOTE] >>>>>>> Release Apache CloudStack 4.1.0 (fifth round)) >>>>>>> >>>>>>> Ilya, >>>>>>> >>>>>>> I'm breaking off a new thread for this discussion. If you want >>>>>>> to discuss the design options presented in the jira, this would >>>>>>> be a good thread for that. ;-) >>>>>>> >>>>>>> -chip >>>>>>> >>>>>>> On Wed, May 29, 2013 at 06:24:27PM +0000, Musayev, Ilya wrote: >>>>>>>> John, >>>>>>>> >>>>>>>> I clearly see your concern, please review my response under >>>>>>>> CLOUDSTACK- >>>>>>> 2492. >>>>>>>> >>>>>>>> Thanks >>>>>>>> ilya >>>>>>>> >>>>>>>>> -----Original Message----- >>>>>>>>> From: John Burwell [mailto:jburw...@basho.com] >>>>>>>>> Sent: Wednesday, May 29, 2013 10:10 AM >>>>>>>>> To: dev@cloudstack.apache.org >>>>>>>>> Subject: Re: [VOTE] Release Apache CloudStack 4.1.0 (fifth >>>>>>>>> round) >>>>>>>>> >>>>>>>>> -0. I don't believe we should be shipping a release with >>>>>>>>> known clock sync issues (see CLOUDSTACK- >>>>>>>>> 2492<https://issues.apache.org/jira/browse/CLOUDSTACK- >> 2492>). >>>>>>>>> Since the community voted to go forward, I will not cast a -1. >>>>>>>>> However, I feel it is important to highlight operational >>>>>>>>> issues that, in my view, a system such as CloudStack should >>>>>>>>> never knowingly >>>>>>> ship. >>>>>>>>> >>>>>>>>> -John > >
