Bug 159007

Summary:	RFE: Have CMAN detect use of loopback address and refuse to run
Product:	[Retired] Red Hat Cluster Suite	Reporter:	Lon Hohberger <lhh>
Component:	cman	Assignee:	Christine Caulfield <ccaulfie>
Status:	CLOSED ERRATA	QA Contact:	Cluster QE <mspqa-list>
Severity:	high	Docs Contact:
Priority:	medium
Version:	4	CC:	cluster-maint, markus.jeckeln, rkenna
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2006-10-17 14:40:53 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Lon Hohberger 2005-05-27 16:05:54 UTC

Description of problem:

When using 2-node clusters and /etc/hosts is improperly configured in such a way
that the local node name resolves to a loopback address, a split-brain can ensue.

Thus, it would be nice if, when starting, CMAN could check for the improper use
of loopback and abort/not run if this occurs (as well as printing a loud warning).

While the case where this would cause problems in production is probably
astronomically low (this is not a BUG, it's a feature request), it does and has
caused confusing for new installations when configuring the cluster for the
first time.

Comment 1 Lon Hohberger 2005-05-27 16:08:30 UTC

...it does and has caused confusion when configuring the cluster for the
first time.

Making sense is a good thing.

Comment 2 Markus Jeckeln 2005-05-27 16:23:42 UTC

Yes... my installation of RHEL 4 came up with my hostname in /etc/hosts at the
loopback address that came up with the cluster confusion. 

samples on node1

config sample: notworking
127.0.0.1               mynode1 localhost.localdomain localhost
192.168.0.105           mynode2
192.168.0.104           mynode1  #added by myself since i had probs with the cluster

config sample fixed & working
127.0.0.1               localhost.localdomain localhost
192.168.0.105           mynode2
192.168.0.104           mynode1

good thing would me a note in syslog or something like that

greeeeetz markus.jeckeln

Comment 3 Christine Caulfield 2005-05-31 15:08:49 UTC

Added to CVS head and FC4 branches.

Comment 4 Christine Caulfield 2005-06-28 12:37:19 UTC

Added to RHEL4 branch so it should appear in U2