vSphere 5.x Notes & Tips - Part II: ESXi Hosts & vCenter Server - Advanced/Troubleshooting:

Hi All ..

In this Part, we'll cover all advanced settings of ESXi hosts and vCenter Server, as well as some troubleshooting guides and hints.
Credits:

• Rick Vanover
• Jason Boche
• Bob Plankers
• Rick Blythe
• Duncan Epping
• nVizor (Don't know the actual name)
  

Let's Start...

1. ESXi Hosts Support Modes:

Support Modes are meant to indicate the way using which, a support or an administer personnel can use to connect to ESXi hosts CLI interface.

The following table summarize it:

2. Restaring ESXi Host Services:

For restarting all services of ESXi host without rebooting it, use SSH Client to connect to the host after enabling SSH access on it (or by using it DCUI), then run the command (./sbin/services.sh restart).

For restarting single service, browse to init.d (cd ./etc/init.d) and you’ll find many agent commands for each service running on the host, like: hostd, vpxa, etc.

3. Changing Windows vCenter Machine Name:

Changing the name of Window vCenter Server is a tedious job, however, sometimes it’s essentially required specially in case of migration to a different environment.

The following article by Rick Vanover is a nice step-by-step guide:

Changing the Name of the vCenter Server -- Virtualization Review

4. Editing Windows vCenter Server Advanced Settings:

For Windows vCenter Server, you can edit its advanced settings from console. In case you entered a false (not typed correctly) setting, you can’t remove it from the console. To remove these false settings, follow the following article -which was written for vCenter 4.0 and it’s applied on vCenter 5.1- by Jason Boche:

vpxd.cfg Advanced Configuration -  boche.net - VMware vEvangelist

For vCenter 5.5, I didn’t try it but I think it works too (confirmation needed).

5. Configuring NTP Source on vCenter Server Appliance (vCSA):

For time synchronization, you can configure external NTP server on vCSA. For vSphere 5.1, it’s done through SSH client and command line by following the official guide below:

Synchronize the vCenter Server Appliance Clock with an NTP Server

Another blog post by Bob Plankers describes it more clearly:

VMware vCenter Server Appliance & NTP — The Lone Sysadmin

In vSphere 5.5, it can be done through vCSA administration web console by following the official guide below:

vSphere 5.5 Documentation Center - Synchronize vCenter Server Appliance with an NTP Sever

6. Implementing CA Certificates on ESXi Hosts & vCenter Server:

In security-restricted environments, vSphere environment can’t depend on self-generated certificates by vSphere components. Deploying trusted certificates, either signed by Enterprise CA or by Public Trusted CA, in vSphere 5.x environment is long and critical operation. That’s why I collected the following KB articles for step-by-step guide for this operation.

1-) vSphere 5.0: Follow the KB article below:

VMware KB: Implementing CA signed SSL certificates with vSphere 5.0 

2-) vSphere 5.1/5.5: First you have to use SSL Certification Automation Tool 1.0.x. Follow the following KB article for its guide:

VMware KB: Deploying and using the SSL Certificate Automation Tool 1.0.x 

Next follow this step-by-step KB article which contains 7 steps to follow and each with its guide article:

VMware KB: Implementing CA signed SSL certificates with vSphere 5.x 

7. Troubleshooting vCenter Server Plugins:

vCenter Sever plugins are GUI for some features integrated with vCenter server, from which you can control these features, edit their settings and even disable these features. Features install plugins are like: AutoDeploy, Update Manager, etc.

For removing unwanted plugin from vCenter Server Home page, follow The KB article from VMware below:

VMware KB: Removing unwanted plug-ins from vCenter Server 

This article is for Windows vCenter Server. I don’t know if it also works for vCenter Linux appliance or not as I didn’t try it (confirmation needed).

For re-registering some plugins in Windows vCenter Server, follow this KB article:

VMware KB: Configuring vCenter Server Support Tools to work in a Wide Area Network 

Although the above article is for another issue, but it contains the steps for re-registering plugins on vCenter Server of AutoDeploy, Syslog Collector, Dump Collector & Authentication Proxy Service. It’s also written for vCenter 5.0, but it worked on vCenter 5.1. I don’t know if it’s working on vCenter 5.5 (confirmation needed).

8. Troubleshooting ESXi Hosts & vCenter Server Issues:

1-) This blog post on VMware Insider Blog by Rick Blythe is collecting top 20 issues of ESXi 5.x:

Top 20 ESXi 5.x issues | VMware Support Insider - VMware Blogs

2-) For troubleshooting ESXi hostd service issues:

VMware KB: Troubleshooting vmware-hostd service if it fails or stops responding on an ESX/ESXi host 

3-) For investigating issues with ESXi disk space:

VMware KB: Investigating disk space on an ESX or ESXi host 

4-) For issues with vCenter server services startup:

VMware KB: Troubleshooting the VMware VirtualCenter Server service when it does not start or fails on vCenter Server…

5-) For vCenter Server database issues:

   VMware KB: vCenter Server installation fails with ODBC and DSN errors 

9. Operability and Feature when vCenter is Down:

Some will wonder: “What features will stop functioning when vCenter is down and what features won’t..??!”. Duncan Epping tried to answer this question in the link below:

http://www.yellow-bricks.com/2008/08/05/what-if-my-virtualcenter-server-crashes/

   Another answer by nVizor (Don’t know the actual nameJ) is also useful:

http://www.nvizor.com/?p=874

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