[ClusterLabs] RHEL-6-7 - Is it possible to run the DLM without Kernel SCTP

[Stephen O'Kane]

Hi,

My cluster setup uses GFS2 file systems, so I need DLM running.
However I have an application that uses it's own SCTP for communication.

This all worked fine until a recent upgrade to 6-7.

It seems that in 6-6 the DLM was changed to use Kernel SCTP.
The application I need will not run if Kernel SCTP is running.

As far as I can tell it should be possible to switch the DLM back to
using TCP, but I can't get it to work.
The DLM now seems to have a hard-coded dependency on SCTP.

The man page for dlm_controld states:
"The  network protocol can be set to tcp, sctp or detect which selects
tcp or sctp
based on the corosync rrp_mode configuration (redundant ring
protocol).  The rrp_mode none results in tcp. "

In the output from corosync-objctl, the rrp_mode is none, so should it
be running with TCP, not SCTP.?

I also added <dlm protocol="tcp"/> to my cluster.conf, but DLM still loads SCTP.
I also tried blacklisting the Kernel SCTP, but DLM will not start without it.

I have searched the archives and some others have had the same, or
similar issues, but they were able to avoid the problem by not
starting DLM. With the GFS2 file system on my cluster I don't have
that option.

What config am I missing? Or is it no longer possible to run DLM over TCP?

Thanks,
TBSteve