[Linux-cluster] relationship corosync + dlm + cman in cluster 3.1.3

Jeroen Koekkoek j.koekkoek at perrit.nl
Wed Jun 22 07:55:02 UTC 2011


I have a question regarding the relationship between Corosync, DLM, and CMAN. Is the following statement correct?

The DLM is a kernel module, dlm_controld is the control daemon.
CMAN is the old messaging layer, and is now stacked on OpenAIS, which in turn is stacked on Corosync.

The DLM does not use CMAN (or Corosync for that matter) to communicate, but does fetch node information from CMAN.

The filesystem (GFS or OCFS2) speaks to the DLM locally (in kernel?) and the DLM takes care of the communication.

Now for the real question.

In the 3.1.3 release dlm_controld still depends on CMAN, but is it safe to say that I can just use Pacemaker and Heartbeat resource agents and only install CMAN so that dlm_controld can query node information?

Or did I misunderstand the documentation?


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