On 02/12/2013 03:57 PM, Dejan Muhamedagic wrote: > Hi, > > On Tue, Feb 12, 2013 at 02:52:58PM +0100, Dennis Jacobfeuerborn wrote: >> On 02/12/2013 03:15 AM, Andrew Beekhof wrote: >>> On Tue, Feb 12, 2013 at 1:01 PM, Dennis Jacobfeuerborn >>> <denni...@conversis.de> wrote: >>>> On 02/12/2013 02:38 AM, Andrew Beekhof wrote: >>>>> On Tue, Feb 12, 2013 at 3:09 AM, Dennis Jacobfeuerborn >>>>> <denni...@conversis.de> wrote: >>>>>> On 02/11/2013 11:30 AM, Andrew Beekhof wrote: >>>>>>> On Mon, Feb 11, 2013 at 9:24 PM, Viacheslav Biriukov >>>>>>> <v.v.biriu...@gmail.com> wrote: >>>>>>>> It is VM in the OpenStack. So we can't use static IP. >>>>>>>> Right now investigating why interface become down. >>>>>>> >>>>>>> Even if you solve that, dynamic IP addresses are fundamentally >>>>>>> incompatible with cluster software. >>>>>>> You're effectively trying to create a cluster out of nodes which >>>>>>> change their name every time they boot. >>>>>> >>>>>> DHCP doesn't necessarily mean a dynamic IP. >>>>> >>>>> In most (if not all) openstack deployments, it does. >>>>> Even better, the static IPs you can assign belong to the physical >>>>> hosts and don't show up inside the guests - so corosync can't bind to >>>>> them. >>>> >>>> You are probably talking about the floating IPs. The primary IPs (usually >>>> in the 10.0.0.0/8 range) of the interfaces however should work fine for >>>> this. There's no magic involved. >>> >>> If they don't show up in 'ip addr', which they don't in openstack >>> guests, then corosync can't use them. >>> There is no way to say "Your address is w.x.y.z but you'll get >>> messages on a.b.c.d". >> >> They show up like like any other interface in 'ip addr'. There is no magic >> involved in any of this. >> The machine gets assigned a primary IP from the assigned network which is >> stored in the dhcp leases database and usually (but not necessarily) it >> gets assigned a floating ip that is reachable from the internet which is >> NATed to the primary IP. >> When the guest boots it discovers its primary IP via dhcp and assignes that >> IP to eth0. >> There is no reason why corosync shouldn't be able to use that IP to address >> the cluster nodes. > > As long as the lease time exceeds the node's uptime :)
The lease time is only relevant for "ad-hoc" ip assignments and not for reserved/bootp dynamic lease entries. That's what I meant when I said dhcp doesn't necessarily mean a dynamic ip. You can create a lease that is tied to the MAC address of a system and then that ip will never be assigned to another system. Regards, Dennis _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
