On Fri, Apr 24, 2009 at 3:32 AM, Imre Oolberg <[email protected]> wrote: > Hallo! > > Thanks for the reply! I am also aware that one popular use of > net.inet.carp.preempt is to control how the computer system as a whole > reacts to errors like one physical interface goes dead. > > 'man carp' says about net.inet.carp.preempt: > > Allow virtual hosts to preempt each other. It is also used to failover carp > interfaces as a group. When the option is enabled and one of the carp > enabled physical interfaces goes down, advskew is changed to 240 on allcarp > interfaces. See also the first example. Disabled by default. > > What i was interested in mainly this time is the so to say practical meaning > of the first sentence, in case how pair of carp interfaces in a carp group > behave while .carp.preempt is not set or is set. > > I decided to dig a little bit deeper because sometimes i cant predict events > when i add another vlan and carp interface to the running system (master for > that particular carp device appears on the wrong side etc). It could be > easily said to me that if your are so interested use the source but i am > sorri the source is not much help for me, i am more about just a user. > > > Imre
Manual failover is simplified: node1 is master with advskew 0 and node2 is backup with advskew 100 Without carp.preempt, you have to take the master down or (I haven't tested this) increase it's demotion counter. With carp.preempt, you can just change its advskew to 150 and watch node2 take over. -HKS
