* Tom Bombadil <[EMAIL PROTECTED]> [2006-09-15 21:57]: > Greetings all... This was probably discussed before, but I couldn't > really find anything in the archives. > > 1) We have a carp0 interface with a few aliases in it, and carp works > fine between master (SERVER-A) and backup (SERVER-B)... until... > > 2) ... we plumb a another new alias into SERVER-B's carp0. Then the > status of carp0 on SERVER-B goes from BACKUP to MASTER, even though the > advskew on SERVER-A is lower (0) than SERVER-B's advskew (127).
this does not work. the aliases on both machines need to be the same, they're all part of the hash. > 3) Now, we have both servers saying carp0 is MASTER, and some of course, since the hashes are different now; they're technically not the same carp group any more. > 4) We haven't tested it, but it seems that if we have added the alias to > SERVER-A first, the problem would still happen, because the hash would > be different as well. > > Question: whats the best way to add an alias to carp, and avoid this > problem? you need to add them at the same time (there is a very short window; do it in parallel, for the value of "parallel" you can reach. one technique is to take down the slave's carp interface, add the alias on the master, add the alias on the slave, take the slave's carp interface up again. -- Henning Brauer, [EMAIL PROTECTED], [EMAIL PROTECTED] BS Web Services, http://bsws.de Full-Service ISP - Secure Hosting, Mail and DNS Services Dedicated Servers, Rootservers, Application Hosting - Hamburg & Amsterdam
