On 10/9/2014 11:57 AM, Jason T. Slack-Moehrle wrote:
Just to clarify. What state is the slave in? If master goes down, how does the slave become active? Just reboot it and let it come up? The wording "slave copy can't be mounted until drdb is stopped" leads me to believe the slave is in some alternate state to be receiving the blocks of data.
the slave is up and running, but the file systems you're replicating are unmounted, and its services are stopped, so you could consider this to be a 'standby' state.
yes, to use drbd, its important that you put your email spools, databases, etc, on dedicated file system(s), NOT on the OS root file system. I generally use lvm for all this.
a cluster management package, such as the ones suggested by another poster, would take care of all this for you (once you have things setup properly), if the master fails, it would 'activate' the slave, switch its IP[*] over to be the 'production' system, and mount its file systems, starting its services (mysqld, postfix, etc) per your configuration.
[*] typically, you use THREE IP addresses for a HA cluster. a unique IP for each system, used only for management, and a 'service' IP used for the production accesses, which is held by the currently active system. when the master fails, the slave adopts this service IP.
-- john r pierce 37N 122W somewhere on the middle of the left coast _______________________________________________ CentOS mailing list CentOS@xxxxxxxxxx http://lists.centos.org/mailman/listinfo/centos
