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vSphere Diagnostic Tool

version 1.1.6 — July 25, 2023

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vSphere Diagnostic Tool is a python script that runs diagnostic commands on the vCenter Server Photon Appliance to return useful troubleshooting data while running within the confines of the local environment with out upstream dependencies.

The motivation behind this tools is to provide multiple Pass/Fail tests to quickly facilitate the rapid isolation of issues encountered in the vSphere environment.

This tool has already been tested by a select group within Support to assist us in looking for bugs as well as provide feedback to the vSphere product team.
The tool itself is currently a set of self contained python and bash scripts that can perform the following tests for vCenter Server Appliance 6.5 or newer:

  • vCenter Basic Info
  • Lookup Service Check
  • AD Check
  • vCenter Certificate Check
  • Core File Check
  • Disk Check
  • vCenter DNS Check
  • vCenter NTP Check
  • vCenter Port Check
  • Root Account Check
  • vCenter Services Check
  • VCHA Check

We use a simple Pass/Warning/Fail status for each test as well as include KBs or other knowledge sources for Warning and Fail results which provides next steps to solving the issue.

Each test should be self-explanatory in its meaning, findings, and directions. If any check isn’t clear in its direction, please report the issue to our team at project_pulse@vmware.com and we will address it.

This tool is considered to be in the Alpha phase so it is possible that false positives could be present, though we haven't encountered any to date. Please provide any and all feedback.

The team are continuing to add new capabilities and checks into this tool as we have a backlog of over 100 new features that we are developing. We have a long term goal to have this tool made available in all current and future VMware products with PhotonOS appliances as well as ESXi.

Installing and running VDT


vCenter Server Appliance 6.5 or Newer


1) Download the ZIP file from the link on the top of this page.

2) Upload the ZIP file to the vCenter system to be analyzed.

3) Use the file-moving utility of your choice (WinSCP for example) to copy the entire ZIP directory to the /root directory.

NOTE: If you have troubles connecting to a vCenter appliance using WinSCP, please see Error when uploading files to vCenter Server Appliance using WinSCP

4) Change directory to the location of the file, and unpackage the zip:

$ cd /root/
$ unzip vdt-version_number.zip

5) To run the tool, first make sure you have unzipped the ZIP file, and have changed to the newly created directory for Pulse/VDT. Then, run the following command:
$ python vdt.py
The tool will prompt for the password for administrator@sso.domain. Many checks will run even if credentials are not supplied.

Installing and running VDT

Review the output by scrolling up and down in the window. Each test should be self-explanatory in it's meaning, findings, and directions. If any check isn't clear in its directions, report the issue to project_pulse@vmware.com and our team will address it.


Version 1.16

General Improvements:
- Increased check timeout from 10 to 20 seconds
- Fixed an issue where the version/topology was identified incorrectly

- In order to check for a newly discovered issue, a check of the Domain Functional Level (DFL) has been introduced.

VC Certificate Check
- Now checks for empty subject key identifier
- Introduced a new check for the count of CRLs in TRUSTED_ROOT_CRLS

    v1.1.5 Release Notes:

    vdt-v1.1.5-05_01_2023.zip - SHA256 - 57536f2e572ea42cc0fdb8049b288db75474add8b355624f5a792eee99a4446e

    General Improvements:

  • VDT now supports 8.0 U1!
  • VDT 1.1.5 will no longer support vCenter 6.7, although many checks will still work. 1.1.4 will remain available for anyone still needing it on the 6.x product line.
  • Credentials are now validated at the start. The user is notified that checks requiring authentication will not run if password validation fails 3x times.
  • The default timeout behavior has changed. It now prompts a user to skip the check or let it run, instead of requiring the --force flag.
  • VC Database Check:

  • The VCDB check now shows statistics levels as well as tasks and event retention policies.
  • The VCDB check output is now in line with the results from KB 1028356.
  • VC VMDIR Check:

  • The vmdir check now includes ELM partner information and tests port connectivity over 389, 443, 2012, and 2020 to them. The old port check has been removed in favor of this.
  • The vmdir check now looks for stale (native) PSC HA config in the likewise registry
  • VC Certificate Check

  • Certificate expiry time is now displayed with each certificate message.
  • The vmdir cert from 6.0 is no longer included in the list of certificate checks
  • Bug fixes:

  • VDT now decodes to utf-8 instead of ascii to avoid parsing errors
  • Updated KB references

vdt-v1.1.4.zip - SHA256 - 992F380B2AD0BDB5ACDA0E60A3B3830C806C6B2B8369427FC6A8199CF99A433F

    v1.1.4 Release Notes:

    VC Disk Space Check:

  • Now ignores proc
  • VC vmdir Check:

  • Fixed issue with special characters in password
  • VC Info Check:

  • Reformatted output and added external PSC output
  • VC Core Check:

  • Enhanced core file check

vdt-v1.1.3.zip - SHA256 -f91fdf32fff192cdf26ea664e5b521225fd8e746ba1cf897fc3030341b8aefd3

    v1.1.3 Release Notes:
  • Fixed issue with encoding compatibility in VC6.5
  • VC Cert Check:

  • Fixed error when root cert has no key usage

vdt-v1.1.2.zip - SHA256 - 60dfaaca9bcc864e0a422bb678bac5fa89e1b68a65e19854969b262bb0632803

    v1.1.2 Release Notes:
      House Keeping/General:
    • Most tests timeout at 10 seconds by default. Use -f to bypass timeouts
    • Title of check now displays before it actually runs
    • No longer causes problems when password contains certain special characters
    • VC Cert Check:

    • Resolved issue encountered when cert contains non-ascii characters

vdt-v1.1.1.zip - SHA256 - 390982e6edaf9d04040bea78c79811d9256bc99bf9e57cf5d5a99f2495f05881

    v1.1.1 Release Notes:
  • Initial version launched as Fling.

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