VM becomes unresponsive or hangs due to SCSI reservation conflicts

Products

• VMware vSphere ESXi

Issue/Introduction

• Virtual machines are unresponsive to tasks or appear to be frozen/hang.
• Tasks performed on the virtual machine fail, timeout, or do not start.
• Error messages n ESXi /var/run/log/vmkernel.log containing RESERVATION CONFLICT or Error status H:0x0 D:0x18 P:0x0

Environment

VMware vSphere ESXi

Cause

SCSI reservation conflicts occur when one host in a cluster has placed a SCSI reservation on a LUN, preventing all other nodes from accessing it. For more information, see KB Resolving SCSI reservation conflicts.

Resolution

Clear the reservation by performing a LUN reset on the affected device:

vmkfstools --lock lunreset /vmfs/devices/disks/naa.############################

To identify the affected LUN and NAA ID, see KB Resolving SCSI reservation conflicts.