Bug 1332692

Summary:	Document avoiding DHCP for corosync nodes
Product:	Red Hat Enterprise Linux 7	Reporter:	Steven J. Levine <slevine>
Component:	doc-High_Availability_Add-On_Reference	Assignee:	Steven J. Levine <slevine>
Status:	CLOSED CURRENTRELEASE	QA Contact:	ecs-bugs
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.3	CC:	abeekhof, jruemker, kgaillot, rhel-docs
Target Milestone:	rc	Keywords:	Documentation
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-11-07 21:35:48 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Comment 2 Steven J. Levine 2016-09-15 16:17:26 UTC

There was no obvious place to add this warning to the Pacemaker reference -- I could add a "considerations" section to the overview and include this, but at this point that would be the only consideration in that section.  Maybe as we come up with more...

So I added a note to the only place we really say anything about corosync, when we talk about the Pacemaker configuration files in Section 1.4.

Does this note address the problem?

http://jenkinscat.gsslab.pnq.redhat.com:8080/job/doc-Red_Hat_Enterprise_Linux-7-High_Availability_Add-On_Reference%20%28html-single%29/lastSuccessfulBuild/artifact/tmp/en-US/html-single/index.html#s1-installation-HAAR

(Looking at it again it still looks wrong.  But can I really have an entire section called "Do not use DHCP with corosync"?

Comment 3 Steven J. Levine 2016-09-15 16:27:01 UTC

Update:  I do have another consideration: 16-node limit on clusters.

So I will add a section called something like "cluster configuration considerations" and move this note there, along with the node-limit.

I'll update this BZ when that gets done, in just a bit.

Comment 4 Steven J. Levine 2016-09-15 16:42:51 UTC

The two new considerations are now section 1.5:

http://jenkinscat.gsslab.pnq.redhat.com:8080/job/doc-Red_Hat_Enterprise_Linux-7-High_Availability_Add-On_Reference%20%28html-single%29/lastSuccessfulBuild/artifact/tmp/en-US/html-single/index.html#s1-configfileoverview-HAAR

Ken: Could you look that new small section over for approval/review?

Comment 5 Ken Gaillot 2016-09-16 16:31:21 UTC

(In reply to Steven J. Levine from comment #4)
> The two new considerations are now section 1.5:
> 
> http://jenkinscat.gsslab.pnq.redhat.com:8080/job/doc-
> Red_Hat_Enterprise_Linux-7-High_Availability_Add-On_Reference%20%28html-
> single%29/lastSuccessfulBuild/artifact/tmp/en-US/html-single/index.html#s1-
> configfileoverview-HAAR
> 
> Ken: Could you look that new small section over for approval/review?

The only change I would make is to say that the 16-node limit applies to full cluster nodes. The cluster may be expanded beyond that using Pacemaker Remote nodes.

Comment 6 Steven J. Levine 2016-09-16 18:54:08 UTC

I have updated that caveat as follows:

Red Hat does not support cluster deployments greater than 16 full cluster nodes. It is possible, however, to scale beyond that limit with remote nodes running the pacemaker_remote service. For information on the pacemaker_remote service, see Section 9.3, “The pacemaker_remote Service”.