Datastore /vmfs/volumes/########-########-####-############ is showing 'NULL' on both vCenter Server UI and ESXi UI.

Products

• VMware vSphere ESXi

Issue/Introduction

• vCenter Server and/or ESXi host GUI may display volume state as "NULL".  
  
  
• You may see an error similar to:

• vmkernel logs will show error similar to:  /var/run/log/vmkernel.log

2025-06-15T00:38:57.194Z In(182) vmkernel: cpu0:2098184)ScsiDeviceIO: 4672: Cmd(0x45bb03829b80) 0x28, CmdSN 0x54 from world 2099661 to dev "naa.################" failed H:0x0 D:0x2 P:0x0 Valid sense data: 0x3 0x11 0x0 Medium Error, LBA: 56576

Environment

vCenter Server 8.0.x
vSphere ESXi 8.0.x

Cause

There are signs of failed I/O operations (I/O error messages), indicating that some read attempts have failed. The Sense Data (0x3 0x11 0x0) confirms a medium error, suggesting the storage device may need additional health checks. File I/O errors related to the LUN could potentially affect accessibility.

Resolution

Verify Storage Health

Run esxcli storage core device smart get -d naa.################ to check SMART status of the lun in question.

• If SMART reports high reallocated sectors, the disk is likely failing.  If this is the case,  customer should contact the hardware vendor to replace the failing disk.
• If SMART data shows pending failures, immediate disk replacement is recommended.
• If the disk is part of a RAID group, replacing it proactively can prevent further degradation.

Additional Information

ESXi S.M.A.R.T. health monitoring for hard drives