Updating `devices` value for fence_scsi or fence_mpath results in a restart of the cluster resources

Environment

• Red Hat Enterprise Linux 8, 9 or 10 (with the High Availability or Resilient Storage Add-on)
• High Availability Pacemaker Cluster
• fence_scsi or fence_mpath stonith device

Issue

• Even with the pcs packages with same or higher version as mentioned in KCS article, the cluster resources still restarts resulting in outage : Can I add or remove devices to a fence_scsi or fence_mpath device without restarting the cluster or all the resources?

Resolution

• This appears to be a known bug and it is being investigated in this Bug/Jira issue : This content is not included.RHEL-70283
• As of today 16th December 2025, the status of the bug is In Progress as Engineering team is actively working on the fix release.

Workaround :

• Untill bug errata is released, use the below commands for updating the fence_scsi or fence_mpath stonith devices in the scheduled downtime window to avoid the unexpected issues as updating will cause the restart of all the cluster resources.

• For fence_scsi:

  pcs stonith update-scsi-devices <stonith id> set <path to scsi device>
  

• For fence_mpath:

  pcs stonith update-scsi-devices <stonith id> set <path to mpath device>
  

Root Cause

• Pacemaker cluster uses hashes to efficiently detect changes in resource configurations without comparing the entire configuration file

• While addition of new storage device, cluster will update the hash and If a hash of the currently configured parameters does not match the with the previously available hash, that means the resource configuration changed since the action was performed and the resource must be reloaded or restarted.

  Nov 12 13:16:35 node_01 pacemaker-schedulerd[5789] (rsc_action_digest_cmp)      info: Parameters to 0ms-interval start action for stonith_resource on node_01-clus changed: hash was b2611ce1d0000d04d337378fd9a17777 vs. now 8c729b555544ae16a4a2af83c9222222 (reload:3.19.0) 0:0;75:0:0:e4986c0f-44e7-44ee-9e5b-3a127d89331f
  

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