Objective 3.4 – Utilize Advanced vSphere Performance Monitoring Tools

Knowledge - Identify Hotkeys And Fields Used With resxtop/esxtop
"?" and "h" brings up syntax help

 There are eight display modes,

• c: cpu
• i: interrupt
• m: memory
• n: network
• d: disk adapter
• u: disk service
• v: disk VM
• p: power mgmt

Knowledge - Identify Fields Used With vscsiStats

 There are five types of data you can gather with vscsiStats

• ioLength
• seekDistance
• outstandingIOs
• latency
• interarrival

Skills and Abilities - Configure esxtop/resxtop Custom Profiles
A custom profile can be useful if you regularly use a specific set of counters,  you simply set the desired display in esxtop, then issue a W to write configuration to a file.

To open esxtop with the saved configuration,  start and pass parameter
            esxtop –c /esxtop50rc
Skills and Abilities - Determine use cases for and apply esxtop/resxtop Interactive, Batch and Replay modes

Interactive Mode
Is useful for troubleshooting when you can recreate an issue and need to find the cause.

Batch Mode
Is useful for looking those issues which occur but you are not sure what causes it and therefore you are not sure when to be watching.


Replay Mode
Is useful for passing to other people to analyse using esxtop.
  
Skills and Abilities - Use vscsiStats to gather storage performance data

List all VMs residing on the host and list all of there virtual scsi disks,  this command is also used to obtain the worldGroupID for the VM you would like to gather data on.

vscsiStats -l

Once you have the  worldGroupID you can start gathering data

vscsiStats -s -w <worldID> 

To view the data you have gathered for a particular VM interactively

vscsiStats -p all -w <worldID> 

To export the data to use in excel or similar

vscsiStats -p all -w <worldID> > filename.csv 

Once you have enough data and want to stop gathering

vscsiStats -x -w <worldID>

Skills and Abilities - Use esxtop/resxtop to collect performance data   

Batch mode can be initiated by starting esxtop with the -b parameter,  be sure to redirect output to a file,  and set an interval and end.

To run for 10 minutes you would issue a command such as,  sample every 2 seconds for 300 iterations total 600 seconds.
esxtop -b -d 2 -n 300 > esxtopbatch.csv.gz



You can then view the contents of file in one of a number of tools such as Windows Perfmon or VisualEsxtop.

To gather data to be replayed into esxtop we use vm-support,  example syntax to gather ten minute of data


vm-support -p -d 300 -i 2 -W workingDirectory



Once we have the data captured,  browse to the working directory and extract the contents of the tar/gunzip file:
    tar -xzf filename.tgz

To replay the data with esxtop,  locate the snapshot folder within the extracted file directory.
    esxtop -r PathToExtractedContents

Skills and Abilities - Given esxtop/resxtop output, identify relative performance data  for capacity planning purposes
Interpreting esxtop 4.1 Statistics

The goal of capacity planning includes identifying peak load utilization for your environment. Esxtop batch logs of performance statistics should be scheduled during a window of activity that demonstrates peak utilization.

CPU and memory capacity can be viewed relatively well in esxtop, as can disk io,  however disk space capacity cannot be well measured.