This Blog is to share our knowledge and expertise on Linux System Administration and VMware Administration

Sunday, November 12, 2017

Performance collection tools to gather data for fault analysis in VMware

This article explains how to use performance collection tools to gather data for analysis of faults such as:
    Unresponsive ESX hosts
    Unresponsive virtual machines
    ESX host purple diagnostic screens

Why gather performance data for a fault?

If the diagnostic logs do not help you determine the cause of a fault, you may need to use performance collection tools to gather further data for analysis. Set up performance collections tools to gather data about faults that may occur.

Performance gathering tools

VMware recommends the following tools for gathering performance data: 

The top utility provides a list of CPU-intensive tasks for the ESX host Service Console.
Use top in batch mode for Fault troubleshooting by directing the output to a file so that it can be reviewed after a recurrence.

Note: The top command is not available for ESXi.
To run the top utility, run the command:

# top –bc –d <delay in seconds> [–n <iterations>] > output-perf-stats-file.txt

Use the information in the output file to identify any trends before the fault. 

The esxtop tool provides performance statistics for the entire ESX/ESXi host. It provides details of network, storage, CPU, and memory load from the VMkernel perspective. It provides details on a VMkernel world basis.
To collect the data over long periods of time, run esxtop in batch mode. Direct the output to a file so that it can be reviewed after the fault.

To run the esxtop tool, run the command:

# esxtop –b –d <delay in seconds> [-n <iterations>] > output-perf-statistics-file.csv

Like esxtop, the resxtop tool provides performance statistics for a specified ESX host in the network. It provides the same performance information as esxtop and may be used either after deploying the VMware vSphere Management Assistant (vMA) virtual appliance or installing the VMware Command-Line Interface (vCLI). 

To run the resxtop tool and collect batch performance data, log into the vMA or open the vCLI, and execute the command:

# resxtop [server] [vihost] [portnumber] [username] -b -d <delay in seconds> [-n <interations>] > output-perf-statistics-file.csv

vm-support -s

Use the vm-support command with the -s parameter to collect performance statistics, system configuration information, and logging. Submit the file generated by this command to VMware Support for further assistance, if required. 

Performance Monitor (PERFMON.EXE)

Microsoft's Performance Monitor is a utility that comes with every Microsoft Windows NT-based Operating System. This utility can be used to monitor local and remote Microsoft Windows machines. It can log performance data and display data from logs or real-time data.

This utility is useful when reviewing data collected from the esxtop tool and for troubleshooting virtual machine unresponsiveness. When using Performance Monitor for virtual machine unresponsiveness, collect the data remotely from another Microsoft Windows machine so that the utility does not affect the data being gathered.
For more information about Performance Monitor on your specific version of Windows, refer to Microsoft support sites.