[ClusterLabs] ERROR: This Target already exists in configFS

[Bryan K. Walton]

I'm building a storage cluster with DRBD 9, Pacemaker, LVM, and iSCSI.
I have two storage nodes in a primary/secondary configuration.

I'm trying to configure Pacemaker to create and manage an iSCSI target
and LUN.  I'm giving it the following commands:

pcs resource create targetRHEVM ocf:heartbeat:iSCSITarget \
	iqn="iqn.2019-02.com.leepfrog:storage.rhevm" \
	allowed_initiators="iqn.1994-05.com.redhat:3d066d1f423e \
	iqn.1994-05.com.redhat:84f0f7458c58" \
	--group ISCSIGroup

And:

pcs resource create lunRHEVM ocf:heartbeat:iSCSILogicalUnit \
	target_iqn=iqn.2019-02.com.leepfrog:storage.rhevm lun=0 \
	path=/dev/storage/rhevm \
	--group ISCSIGroup


But when I do that, the resource fails to start:
Operation start for targetRHEVM (ocf:heartbeat:iSCSITarget) returned:
'unknown error' (1)
 >  stderr: Feb 12 14:06:19 INFO: Parameter auto_add_default_portal is
 >  now 'false'. 
  >  stderr: Feb 12 14:06:20 INFO: Created target
  >  iqn.2019-02.com.leepfrog:storage.rhevm. Created TPG 1. 
   >  stderr: Feb 12 14:06:20 ERROR: This Target already exists in
   >  configFS

The ONLY way I've been able to get this to work is to create the iscsi
target manually, on both storage nodes, using targetcli.  Then, manually
create the ACLs on both nodes, using targetcli.  And then, finally, ONLY
create a LUN resource in Pacemaker.

Surely, I'm doing something wrong, but I can't figure out what that is.
What might I be doing wrong that is preventing Pacemaker from creating
the target resource?

Can you assist me, please?

Thanks!
Bryan