LUNs are not attaching to all the hosts

Products

• VMware vSphere ESXi 8.0

Issue/Introduction

• A LUN presented from a SAN appears in vCenter with an 'Attached' operational state on some ESXi hosts, but a 'Detached' state on others, even after performing a storage rescan.

Environment

VMware vSphere ESXi 8.x

Cause

• This persistent 'Detached' state typically occurs when a LUN, previously manually detached from a host, is subsequently re-presented to that same host, requiring manual intervention to reactivate it.
  
  
• In /var/run/vmkernel.log, the LUN was explicitly marked as 'administratively turned off' on the affected hosts.
  
  cpu33:2097876)ScsiDeviceIO: 11941: Get VPD 86 Inquiry for device "naa.##############" from Plugin "NMP" failed. Not supported
  cpu33:2097876)ScsiDeviceIO: 10535: QErr is correctly set to 0x0 for device naa.##############.
  cpu41:2098365)WARNING: ScsiDeviceIO: 4576: ModeSense 0x1a request failed - blocking page:0x1c subpage:0x2 naa.##############
  cpu33:2097876)ScsiDeviceIO: 11042: Could not detect setting of sitpua for device naa.##############. Error Not supported.
  cpu33:2097876)ScsiDevice: 1832: Device naa.##############  has been turned off administratively.
  cpu33:2097876)ScsiDevice: 4882: Failed to register for 'REPORTED LUNS DATA CHANGED' unit attention for device:naa.##############. Reason: Not found

Resolution

• To bring the LUN back online and make it accessible:
  Execute the following esxcli command on each affected ESXi host.
  esxcli storage core device set --state=on -d NAA_ID
  
  
• To permanently remove the device from the ESXi host (if the device is no longer needed):
  
  
  1. To list the permanently detached devices:
     
     esxcli storage core device detached list
     
     Output will be similar to:
     
     Device UID State
     ---------------------------- -----
     naa.50060########################## off
     naa.60060########################## off
      
  2. To permanently remove the device from the ESXi:
     Execute this command for each NAA_ID you wish to remove. 
     
     esxcli storage core device detached remove -d NAA_ID
     
     For example:
     esxcli storage core device detached remove -d naa.50060##########################