A VMFS datastore is inaccessible

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• A VMFS datastore is in a inaccessible state:
  
• The backend LUN is not being discovered within the host's storage devices:
  

Environment

VMware vSphere 7.0.x

Cause

• The datastore is inaccessible as the backend LUN is not visible to the ESXi host. 

• SCSI code H:0x1 below from the var/logs/vmkernel.log indicates the ESXi host is lost connection to the LUN. The LUN is no longer visible to the host.

  ####-##-##T##:##:##.###Z cpu5:#######)WARNING: vmw_psp_rr: psp_rrSelectPath:2270: Could not select path for device "naa.################################".

  ####-##-##T##:##:##.###Z cpu5:#######)WARNING: NMP: nmp_IssueCommandToDevice:5950: I/O could not be issued to device "naa.################################" due to Not found

  ####-##-##T##:##:##.###Z cpu5:#######)ScsiDeviceIO: 4176: Cmd(0x############) 0x9e, CmdSN 0x879a75a from world 0 to dev "naa.################################" failed H:0x1 D:0x0 P:0x0

  Host Status

  [0x1]

  NO_CONNECT

  This status is returned if the connection is lost to the LUN. This can occur if the LUN is no longer visible to the host from the array side or if the physical connection to the array has been removed.

   

  ####-##-##T##:##:##.###Z cpu5:#######)ScsiDeviceIO: 4176: Cmd(0x############) 0x1a, CmdSN 0x879a75d from world 0 to dev "naa.################################" failed H:0x1 D:0x0 P:0x0

  ####-##-##T##:##:##.###Z cpu5:#######)WARNING: ScsiDeviceIO: 12155: READ CAPACITY on device "naa.################################" from Plugin "NMP" failed. I/O error

  - The partition table is unreadable as seen above. 

Resolution

• To resolve this issue:

  1. A storage rescan or reboot on the host restores access to the device/datastore.

  2. If issues persists engage your storage vendor support to investigate further on why the LUN is not accessible to the host.