I'm wondering if it is possible to have both LVS-NAT-style and
LVS-DR-style realservers running for one virtual service (at the same time)?
The reason I ask is that I'm in the process of implementing a new web
system (primarily port 80). My existing LVS system uses LVS-NAT, but I
want to move to LVS-DR. I have the LVS-DR realservers working fine using
a different virtual IP but using the same web content and talking to the
same databases (the LVS-DR realservers have an IP in the LVS-NAT private
network, so can NFS-mount the shared web document root).
I'd really like to run my two existing LVS-NAT realservers and my two
new LVS-DR realservers simultaneously for a while. The fact that you
specify whether to use 'masq' (NAT) or 'gate' (DR) in ipvsadm's "add a
realserver" command (i.e. 'ipvsadm -a ...') makes me think it might be
possible... I'd test it myself, but I'd have to either schedule an
outage or build a dev system, so I wonder if anyone knows?