[nycbug-talk] ucarp question

[Yarema]

--On Tuesday, September 19, 2006 6:12 PM -0400 Isaac Levy <ike at lesmuug.org> 
wrote:

> On Sep 17, 2006, at 8:02 PM, Yarema wrote:
>
>> What does your /etc/vip-up.sh script actually look like?  Does
>> it have the requisite ifconfig ... alias command to actually
>> assign the virtual IP to the interface in question?
>
> Oh.  Boy I feel stupid.  So UCarp is REALLY just the Carp, I feel
> like an idiot, I thought UCarp brought up the ipalias all by
> itself. (*doh!*)  But it ONLY does the Carp.  Boy I feel stupid.
>
> So, I'll do it again when I'm back touching that machine again,
> adding the appropriate ifconfig alias statements to the up and
> down scripts.

Well, like you said.. the documentation is a little on the thin side with 
ucarp.. there's not even a man page..

you'll have to experiment with this, but I think the /etc/vip-{up,down}.sh 
scripts should add/remove the virtual IP aliases on *all* the interfaces 
for which you want failover.  Not just the interface which stops responding 
to the heartbeat.  I believe that's how the kernel carp(4) does it.

That being said I think more apropos names for the up/down scripts would be 
/etc/start_if.carp as documented in rc.conf(5).  If you write the scripts 
just right they might work for both ucarp and carp(4)..

But I think the main advantage of ucarp over carp(4) is that you can do 
whatever you need in the up/down scripts.  carp(4) does not have this type 
of flexibility.

-- 
Yarema
http://yds.CoolRat.org/