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

[Stephen O'Kane]

Thanks for the information John

 Much appreciated.

On 12 November 2015 at 09:39, Stephen O'Kane <stephenpokane at gmail.com> wrote:
> 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