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 > > > > > > > > > > > > > > > > > > > > > > > >
