[ClusterLabs] Question about fencing

[Ken Gaillot]

On Wed, 2019-04-17 at 15:17 -0600, JCA wrote:
> Here is what I did:
> 
> # pcs stonith create disk_fencing fence_scsi pcmk_host_list="one two"
> pcmk_monitor_action="metadata" pcmk_reboot_action="off"
> devices="/dev/disk/by-id/ata-VBOX_HARDDISK_VBaaa429e4-514e8ecb" meta
> provides="unfencing"
> 
> where ata-VBOX-... corresponds to the device where I have the
> partition that is shared between both nodes in my cluster. The
> command completes without any errors (that I can see) and after that
> I have
> 
> # pcs status
> Cluster name: ClusterOne
> Stack: corosync
> Current DC: one (version 1.1.19-8.el7_6.4-c3c624ea3d) - partition
> with quorum
> Last updated: Wed Apr 17 14:35:25 2019
> Last change: Wed Apr 17 14:11:14 2019 by root via cibadmin on one
> 
> 2 nodes configured
> 5 resources configured
> 
> Online: [ one two ]
> 
> Full list of resources:
> 
>  MyCluster	(ocf::myapp:myapp-script):	Stopped
>  Master/Slave Set: DrbdDataClone [DrbdData]
>      Stopped: [ one two ]
>  DrbdFS	(ocf::heartbeat:Filesystem):	Stopped
>  disk_fencing 	(stonith:fence_scsi):	Stopped

Your pcs command looks good to me. I'm perplexed why everything is
stopped.

Check the logs on the DC (node one in the output above) for error or
warning messages around this time. /var/log/messages is usually
sufficient, but the detail log will have (obviously) more details
(usually /var/log/pacemaker.log or /var/log/cluster/corosync.log).

> Daemon Status:
>   corosync: active/enabled
>   pacemaker: active/enabled
>   pcsd: active/enabled
> 
> Things stay that way indefinitely, until I set stonith-enabled to
> false - at which point all the resources above get started
> immediately.
> 
> Obviously, I am missing something big here. But, what is it?
> 
> 
> On Wed, Apr 17, 2019 at 2:59 PM Adam Budziński <
> budzinski.adam at gmail.com> wrote:
> > You did not configure any fencing device.
> > 
> > śr., 17.04.2019, 22:51 użytkownik JCA <1.41421 at gmail.com> napisał:
> > > I am trying to get fencing working, as described in the "Cluster
> > > from Scratch" guide, and I am stymied at get-go :-(
> > > 
> > > The document mentions a property named stonith-enabled. When I
> > > was trying to get my first cluster going, I noticed that my
> > > resources would start only when this property is set to false, by
> > > means of 
> > > 
> > >     # pcs property set stonith-enabled=false
> > > 
> > > Otherwise, all the resources remain stopped.
> > > 
> > > I created a fencing resource for the partition that I am sharing
> > > across the the nodes, by means of DRBD. This works fine - but I
> > > still have the same problem as above - i.e. when stonith-enabled
> > > is set to true, all the resources get stopped, and remain in that
> > > state.
> > > 
> > > I am very confused here. Can anybody point me in the right
> > > direction out of this conundrum?
> > > 
> > > 
> > > 
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-- 
Ken Gaillot <kgaillot at redhat.com>