On 12/06/2012 03:26 AM, Lars Marowsky-Bree wrote: > On 2012-12-06T00:02:28, Hermes Flying <[email protected]> wrote: > >> Hi, >> I was wondering how does fencing/STONITH work in a VM environment? Obviously >> the nodes running inside a VM should run in separate machines but can we >> STONITH a node that is running inside a VM? > > I'd suggest to use something like SBD or fence_sanlock (depending on > which distribution you run, we have multiple implementations of the > wheel).
fence_sanlock requires a "hardware" watchdog to work reliably. If you can get the host/hypervisor to emulate one outside the VM, that should work. Alternatively, fence_xvm and fence_virsh would work. The trick is to ensure multicast messages travel between the hardware nodes, so you need to get your networking right. >> Also what is the best practice in regards to VMs and HA? > > If you're running HA *within* the VMs, just treat them like you'd treat > physical nodes. Except for choosing an appropriate fencing mechanism, > nothing special. > > Oh - if your hypervisor does something like live migrations, make sure > the timeouts of the cluster don't trigger during one. But normally > that's not a problem. Very important point. -- Digimer Papers and Projects: https://alteeve.ca/w/ What if the cure for cancer is trapped in the mind of a person without access to education? _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
