ESXi Host(s) getting disconnected from vCenter Server

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

ESXi Host(s) is disconnected from vCenter Server with entries similar to the below in vpxa.log

Note: vpxa.log is located on the ESXi host in /var/run/log/vpxa.log

Error returned by expat parser: not well-formed (invalid token)
while parsing serialized value of type string
at line 7, column 12253
while parsing property "baseUnits" of static type string
while parsing serialized DataObject of type vim.host.NumericSensorInfo
at line 7, column 11996
while parsing property "numericSensorInfo" of static type ArrayOfHostNumericSensorInfo
error vpxa[2105387] [Originator@6876 sub=vpxaInvtHostCnx opID=WFU-66d4eb2f] Can't connect to hostd. Shutting down...

Environment

VMware vSphere ESXi 6.7
VMware vSphere ESXi 6.5
VMware vSphere ESXi 7.0.1

Cause

Due to non-utf8 string in name property of numeric sensor, vpxa shuts down which can cause the ESXi host to get disconnected from vCenter Server.

Resolution

This issue is fixed as below:

•  For vSphere ESXi 6.5, issue is fixed in 6.5 P07. For more information, see VMware ESXi 6.5, Patch Release ESXi650-202102001.
• For vSphere ESXi 6.7, issue is fixed in 6.7 P04. For more information, see VMware ESXi 6.7, Patch Release ESXi670-202011002.
• For vSphere ESXi 7.0, issue is fixed in 7.0 Update 1c. For more information, see VMware ESXi 7.0 Update 1c Release Notes .

Workaround:

To workaround this issue, please disable the cimsvc service on the impacted ESXi Host as showing on the below steps.
Note: Disabling cimsvc service will also turn-off the hardware health monitoring. For more information, see Monitoring Host Health Status.

1. Login to the ESXi Host (root) through SSH using Putty

2. Enter the below command to stop hostd :

# /etc/init.d/hostd stop

3. Navigate to the  /etc/vmware/hostd/ file as the below command.

# cd  /etc/vmware/hostd/

4. Backup the file config.xml as below:

# cp config.xml config.xml.bak

5. Using text editor, edit the file config.xml as below:

# vi config.xml

Look for the value:

<cimsvc>

<path>libcimsvc.so</path>
<enabled>true</enabled>

</cimsvc>

Press i to enter Insert mode.
Change the value "<enabled>true</enabled>" to <enabled>false</enabled> so it should look like :

<cimsvc>

<path>libcimsvc.so</path>
<enabled>false</enabled>

</cimsvc>

Save the file and exit.

6. Enter the below command to start hostd:

# etc/init.d/hostd start

Additional Information

This issue is being checked by Diagnostics for VMware Cloud Foundation.

The check is as follows:

• Product: ESXi
• Log File: vpxa.log
• Log Expression Check "Error returned by expat parser: not well-formed (invalid token)"