[ClusterLabs] newbie questions

[Ken Gaillot]

On 05/31/2016 03:59 PM, Jay Scott wrote:
> Greetings,
> 
> Cluster newbie
> Centos 7
> trying to follow the "Clusters from Scratch" intro.
> 2 nodes (yeah, I know, but I'm just learning)
> <PRE>
> [root at smoking ~]# pcs status
> Cluster name:
> Last updated: Tue May 31 15:32:18 2016        Last change: Tue May 31
> 15:02:21
>  2016 by root via cibadmin on smoking
> Stack: unknown

"Stack: unknown" is a big problem. The cluster isn't aware of the
corosync configuration. Did you do the "pcs cluster setup" step?

> Current DC: NONE
> 2 nodes and 1 resource configured
> 
> OFFLINE: [ mars smoking ]
> 
> Full list of resources:
> 
>  ClusterIP    (ocf::heartbeat:IPaddr2):    Stopped
> 
> PCSD Status:
>   smoking: Online
>   mars: Online
> 
> Daemon Status:
>   corosync: active/enabled
>   pacemaker: active/enabled
>   pcsd: active/enabled
> </PRE>
> 
> What concerns me at the moment:
> I did
> pcs resource enable ClusterIP
> while simultaneously doing
> tail -f /var/log/cluster/corosync.log
> (the only log in there)

The system log (/var/log/messages or whatever your system has
configured) is usually the best place to start. The cluster software
sends messages of interest to end users there, and it includes messages
from all components (corosync, pacemaker, resource agents, etc.).

/var/log/cluster/corosync.log (and in some configurations,
/var/log/pacemaker.log) have more detailed log information for debugging.

> and nothing happens in the log, but the ClusterIP
> stays "Stopped".  Should I be able to ping that addr?
> I can't.
> It also says OFFLINE:  and both of my machines are offline,
> though the PCSD says they're online.  Which do I trust?

The first online/offline output is most important, and refers to the
node's status in the actual cluster; the "PSCD" online/offline output
simply tells whether the pcs daemon is running. Typically, the pcs
daemon is enabled at boot and is always running. The pcs daemon is not
part of the clustering itself; it's a front end to configuring and
administering the cluster.

> [root at smoking ~]# pcs property show stonith-enabled
> Cluster Properties:
>  stonith-enabled: false
> 
> yet I see entries in the corosync.log referring to stonith.
> I'm guessing that's normal.

Yes, you can enable stonith at any time, so the stonith daemon will
still run, to stay aware of the cluster status.

> My corosync.conf file says the quorum is off.
> 
> I also don't know what to include in this for any of you to
> help me debug.
> 
> Ahh, also, is this considered "long", and if so, where would I post
> to the web?
> 
> thx.
> 
> j.