VCAP5-DCA Objective 6.5 – Troubleshoot vCenter Server and ESXi host management

26/09/2012

Objectives

  • Troubleshoot vCenter Server service and database connection issues
  • Troubleshoot the ESXi firewall
  • Troubleshoot ESXi host management and connectivity issues
  • Determine the root cause of a vSphere management or connectivity issue
  • Utilize Direct Console User Interface (DCUI) and ESXi Shell to troubleshoot, configure, and monitor an environment

Troubleshoot vCenter Server service and database connection issues

Official Documentation:

Summary:

I assume this topic refers to the Microsoft Windows based vCenter Server (and not the vCenter Server Appliance.

The VMware VirtualCenter Server is one of many – but probably – the most important Service on the vCenter Server. The actual Service runs under the name: vpxd.exe.

Figure 1 – vCenter Services

VMware has done a good job publishing some very nice KB articles related to troubleshooting the vCenter Service.

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VCAP5-DCA Objective 6.4 – Troubleshoot storage performance and connectivity

26/09/2012

Objectives

  • Use esxcli to troubleshoot multipathing and PSA-related issues
  • Use esxcli to troubleshoot VMkernel storage module configurations
  • Use esxcli to troubleshoot iSCSI related issues
  • Troubleshoot NFS mounting and permission issues
  • Use esxtop/resxtop and vscsiStats to identify storage performance issues
  • Configure and troubleshoot VMFS datastores using vmkfstools
  • Troubleshoot snapshot and resignaturing issues
  • Analyze log files to identify storage and multipathing problems

Use esxcli to troubleshoot multipathing and PSA-related issues

Official Documentation:
vSphere Command-Line Interface Concepts and Examples, Chapter 4 “Managing Storage”, section “Managing Paths”, page 42.

Summary:
Multipathing, PSA and the related commands have been discussed in Objective 1.3 “Configure and manage complex multipathing and PSA plugins”.

See also this post for an graphical overview of the ESXCLI command.

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VCAP5-DCA Objective 6.3 -Troubleshoot Network Performance and Connectivity

16/09/2012

Objectives

  • Utilize net-dvs to troubleshoot vNetwork Distributed Switch configurations
  • Utilize vSphere CLI commands to troubleshoot ESXi network configurations
  • Troubleshoot Private VLANs
  • Troubleshoot vmkernel related network configuration issues
  • Troubleshoot DNS and routing related issues
  • Use esxtop/resxtop to identify network performance problems
  • Analyze troubleshooting data to determine if the root cause for a given network problem originates in the physical infrastructure or vSphere environment
  • Configure and administer Port Mirroring
  • Utilize Direct Console User Interface (DCUI) and ESXi Shell to troubleshoot, configure, and monitor ESXi networking

Utilize net-dvs to troubleshoot vNetwork Distributed Switch configurations

Official Documentation:

Summary:
There is not much official documentation on the net-dvs command. The reason for this is probably because the command is unsupported.

Figure 1

As you can see, most options are not documented. The most common options:

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VCAP5-DCA Objective 6.2 – Troubleshoot CPU and memory performance

10/09/2012

Objectives

  • Troubleshoot ESXi host and Virtual Machine CPU performance issues using appropriate metrics
  • Troubleshoot ESXi host and Virtual Machine memory performance issues using appropriate metrics
  • Use Hot-Add functionality to resolve identified Virtual Machine CPU and memory performance issues

Troubleshoot ESXi host and Virtual Machine CPU and Memory performance issues using appropriate metrics

Official Documentation:
vSphere Monitoring and Performance Guide

Summary:
Both topics will be discussed.

There are four essential resources to an ESXi host; CPU, Memory, Storage and Network. Most critical resource on every ESXi host is Memory.

Methods to view Performance data

  • vSphere Client
    • Performance Tabs on nearly every level (Cluster, Host, VM)
    • Summary Tab on the Host level, Resource Usage
  • CLI

Objective 3.4 discusses the usage of esxtop and presents some useful links. I encourage you to practice a lot with esxtop.
But that’s not all; the most important part is interpreting what you see. VMware Communities “Interpreting esxtop Statistics” is an excellent resource. Get familiar and know about Worlds, %RDY, %CSTP, %MLMTD, %USED, %SYS and %SWPWT.

CPU metrics, what do we monitor?

  • Host level, CPU usage (time physical CPU is used)

Figure 1

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VCAP5-DCA Objective 6.1 – Configure, manage and analyse vSphere log files

04/09/2012

Objectives

  • Generate vCenter Server and ESXi log bundles
  • Use esxcli system syslog to configure centralized logging on ESXi hosts
  • Test centralized logging configuration
  • Analyze log entries to obtain configuration information
  • Analyze log entries to identify and resolve issues
  • Install and configure VMware syslog Collector and ESXi Dump Collector

Generate vCenter Server and ESXi log bundles

Official Documentation:
vCenter Server Host Management Guide, Chapter 8, “System Log Files”, page 91.

Summary:

vCenter Server

To generate vCenter Server log bundles. There are a few ways to get started, but depending on your location in the vSphere Client) options can vary. The best starting points:

  • Menu, Administration, Export System Logs
  • Home, System Logs, the button  “Export System Logs”

From here, you can select where logging should be gathered from.

Optional you can include information from the vCenter Server and your vSphere Client.

Figure 1

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