Can I configure my RHEL High Availability cluster of z/VM guests to use a single fence_zvmip device for nodes spanning multiple LPARs in an SSI cluster?

Solution Unverified - Updated

Environment

  • Red Hat Enterprise Linux (RHEL) 7 with the High Availability Add-On
  • IBM z Systems z/VM guests as cluster members
  • Using z/VM SMAPI power-fencing with fence_zvmip

Issue

  • I have an SSI cluster with multiple z/VM LPARs. Can I use a single fence_zvmip device for all nodes?
  • fence_zvmip succeeds for VMs in one z/VM LPAR but fails for VMs in the other LPAR in an SSI cluster

Resolution

Set up one fence_zvmip device per LPAR hosting a guest that is a cluster member.

See: Administrative Procedure - Configuring z/VM SMAPI Fencing with fence_zvmip for RHEL 7 IBM z Systems Cluster Members.

In the Create STONITH Device(s) step, simply create one STONITH device per LPAR, such as in the example shown there.

# pcs stonith create zvm-smapi1 fence_zvmip ipaddr=zvm-smapi1.example.com login='ZCLUSTER' passwd='ZPASSWD' pcmk_host_map="rhelha-node1.example.com:RHELHA-1;rhelha-node2.example.com:RHELHA-2"
# pcs stonith create zvm-smapi2 fence_zvmip ipaddr=zvm-smapi2.example.com login='ZCLUSTER' passwd='ZPASSWD' pcmk_host_map="rhelha-node3.example.com:RHELHA-3;rhelha-node4.example.com:RHELHA-4"

Root Cause

If the cluster is set up spanning LPARs in a SSI configuration, a fence_zvmip stonith device must be configured for each SSI member. This
is due to the Image_Activate and Image_Deactivate SMAPI functions that are used by the fence agent not considering the SSI as a single system, so the SMAPI workers on one LPAR are unable to activate or deactivate virtual machines on the other LPAR(s).

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