[Linux-cluster] Removing a node from a running cluster

[James Parsons]

isplist at logicore.net wrote:

>Fixed my shut down problems so anyone else having issues, here's how it works.
>
>Man for cman_tool says;
>
>//
>leave;
>
>Tells CMAN to leave the cluster. You cannot do this if there are subsystems 
>(eg DLM, GFS) active.  
>You  should dismount all GFS filesystems, shutdown CLVM, fenced and anything 
>else using the cluster manager before using cman_tool leave.  Look at 
>cman_tool status|services to  see  how  many (and which) services are running.
>\\
>
>Answers all :).
>
WARNING: Shameless Promotion --

Conga does all of these things for you in a browser window...there is a 
dropdown menu on the node page that offers the user the option to have a 
node leave or join a cluster, completely delete a node, reboot a node, 
or use the fence subsystem to fence a node. With one mouse click and a 
confirmation dailog, all neccesary services are checked and shutdown for 
you and the node is removed/deleted/etc.

When you add a new node, you enter the ipaddr/hostname for the new node, 
and then all necessary packages are yummed and installed, all necessary 
services started, and a new configuration file reflecting the new node 
is propagated.

What if you add a node two a two-node cluster that does not use quorum 
disk, you ask? Conga removes the two_node=1 attr from the <cman> tag and 
reminds you that the cluster needs to be restarted...and provides a link 
to the appropriate cluster page where one mouse click and a confirmation 
dialog will restart the whole cluster.

-J