[VMConAWS] Unable to mount FSx server after host reboot.
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[VMConAWS] Unable to mount FSx server after host reboot.


Article ID: 325152


Updated On:


VMware Cloud on AWS


To determine network connectivity and ports required for the FSx mount and remediation

  • FSx mount may fail after a host reboot following a maintenance activity
  • FSx mount may fail with connectivity error. 
<DATE> <TIME>Z pod ERROR   7136b443-2f2f-xxxx-a38f-xxxxxxxxxxxx T-139699683309312 driver.storage.datastore_lib Failed to mount the NAS datastore 'Citrix_Datastore' to the host '192.xxx.xxx.xxx', mount info : (vim.host.MountInfo) {
   dynamicType = <unset>,  
   dynamicProperty = (vmodl.DynamicProperty) [],
   path = '/vmfs/volumes/e4927615-243exxxx',
   accessMode = 'readWrite',
   mounted = false,
   accessible = false,
   inaccessibleReason = '',
   vmknicName = <unset>,
   vmknicActive = <unset>,
   mountFailedReason = 'CONNECT_FAILURE'


The mount failure occurs if the required ports for NFS mount and connectivity are blocked.


The NFS functionality operates as follows:

  • During the mount process, the mount request from the NFS Client (ESXi) is sent to the NFS server on TCP port 111 (portmapper)
  • For port mapping, discovery, and the actual mount procedure is performed on TCP port 635 (mount service) 
  • After successful mounting, TCP port 2049 (NFS data port) is utilized for continuous data traffic in the steady state.

To ensure smooth NFS operations, make sure that the necessary ports for the mount process and data traffic are allowed in the firewall and VPC Security Group. 

Our documentation advises that to facilitate NFS communication, it is recommended to open up the security group for the entire VPC CIDR. You can find detailed instructions on creating transit gateway attachments, configuring routing, and setting up security groups in the provided link FSx-guide

Additionally, AWS documentation provides information about the required ports for NFS communication. You can refer to the following link for further insights on creating security groups to manage access: AmazonFsx-Guide


Additional Information

In the event that the NFS mount fails after a host reboot, VMs utilizing the NFS datastores will cease to function.