"Unknown" status of the NSX prepared host in the NSX manager UI, due to nestdb DOWN

Products

• VMware NSX

Issue/Introduction

• Controller connectivity of host shows "Unknown state" in host details overview of the NSX UI
• Command 'nsxcli -c get controllers'  returns  % Failed to get controller list
• In System > Fabric > Host, the host status shows as Unknown
  In NSX Manager UI 'System > Fabric > Hosts > [Hostname] > View Details > Monitor > Agent Status' shows NSX_NESTDB is Down.
  
• Getting no output when checking the disk space : "df -h" on the host.
• There are no files under the var/run/log folder of the problematic host.
• Restarting the nestdb service will not help and will went into the not running status post restart as well.

Environment

VMware NSX

Cause

Host datastore/disk was not accessible causing the unknown status of the Host on the NSX manager.

Can be check on the root shell of the host using the command : esxcfg-mpath -L (This will show the disk status)

For example dead status on the storage disk :

Resolution

Please contact the hardware vendor to verify the disk status.

Additional Information

Please refer to the similar kbs for nestdb and host unknown status :

• https://knowledge.broadcom.com/external/article/381319/ 
• https://knowledge.broadcom.com/external/article/377757/
• https://knowledge.broadcom.com/external/article/322542/
• https://knowledge.broadcom.com/external/article/407365/