[Pacemaker] SBD fencing - stonith plugin not installed

[Alexandr A. Alexandrov]

Hi!

I am trying to implement SBD fencing in a two-node cluster (having 
shared storage).
Everything is set up as described on linux-ha.org, SBD is working:

# sbd -d /dev/sdb1 list
0       wcs1    clear
1       wcs2    clear

However, when I try to create a stonith resource, I get:

Stack: openais
Current DC: wcs1 - partition with quorum
Version: 1.1.7-6.el6-148fccfd5985c5590cc601123c6c16e966b85d14
2 Nodes configured, 2 expected votes
1 Resources configured.
============

Online: [ wcs1 wcs2 ]


Failed actions:
     stonith_sbd_start_0 (node=wcs1, call=6, rc=5, status=complete): not 
installed
     stonith_sbd_start_0 (node=wcs2, call=6, rc=5, status=complete): not 
installed

Plugin file gets installed into /usr/lib/stonith/plugins/external, and 
seems to be working:

# /usr/lib/stonith/plugins/external/sbd status; echo $?
0

Resource is configured in pacemaker like in the doc -

primitive stonith_sbd stonith:external/sbd
(tried also with device parameter, but it complained that there is no 
such parameter).

Feels like Pacemaker does not find the plugin...
Any thoughts?

Thanks in advance,

Alex.