[ClusterLabs] PCS, Corosync, Pacemaker, and Bind

[Ken Gaillot]

On 03/15/2016 06:47 PM, Mike Bernhardt wrote:
> Not sure if this is a BIND question or a PCS/Corosync question, but
> hopefully someone has done this before:
> 
>  
> 
> I'm setting up a new CentOS 7 DNS server cluster to replace our very old
> CentOS 4 cluster. The old one uses heartbeat which is no longer supported,
> so I'm now using pcs, corosync, and pacemaker.  The new one is running the
> latest 9.10.x production release of BIND. I want BIND to listen on, query
> from, etc on a particular IP address, which is virtualized with pacemaker. 
> 
>  
> 
> This worked fine on the old cluster. But whereas heartbeat would create a
> virtual subinterface (i.e. eth0:0) to support the virtual IP, corosync does
> not do that; at least it doesn't by default. So although the virtual IP
> exists and is pingable, it is not tied to a "physical" interface- ifconfig
> does not find it. And when BIND tries to start up, it fails because it can't
> find the virtual IP it's configured to run on, even though it is reachable.
> I only need IPv4, not IPv6.

The old subinterfaces are no longer neded in linux-land for "virtual"
IPs, which are now actually full-class citizens, just one of multiple
IPs assigned to the interface. ifconfig (or its fashionably new
alternative, "ip addr") should show both addresses on the same interface.

BIND shouldn't have any problems finding the IP. Can you show the error
messages that come up, and your pacemaker configuration?

>  
> 
> So, I'm hoping that there is a way to tell corosync (hopefully using pcsd)
> to create a virtual interface, not just a virtual address, so BIND can find
> it.
> 
>  
> 
> Thanks in advance!