Resource Clusters (RC) lock messages seen in the ESXi host logs

Products

• VMware vSphere ESXi

Issue/Introduction

Resource Clusters (RC) lock messages are seen in the vmkernel.log for the ESXi hosts connected to VMFS datastores.

2024-08-13T23:30:52.045Z In(182) vmkernel: cpu82:2397575)Res6: 2937: 'datastore': RC Lock not free for type 1, return TXN FULL

Environment

VMware vSphere ESXi (All Versions)

Cause

When seen in large numbers in the logs, this can be a side-effect of latency or other SCSI failures on the VMFS datastore.  When seen sparingly in the logs, this can be considered normal.  The VMFS locking mechanism helps ensure the integrity of the data and allows multiple ESXi hosts to access the same block regions in succession.

Resolution

If RC locks are seen in large numbers, look for other failures in the vmkernel.log.  High latency or other SCSI failures can lead to elevated RC lock messages.  However, the RC lock messages are not usually the cause of the storage failures as they are a normal mechanism within the VMFS framework.

Additional Information

For more information on Resource Clusters (RC) locks see VMware vSphere VMFS p.19