Collecting performance snapshots using vm-support in ESX and ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

This article provides information on collecting performance snapshots in ESX and ESXi.

Environment

VMware vSphere ESXi 6.5

VMware vSphere ESXi 6.7

VMware vSphere ESXi 7.0

VMware vSphere ESXi 8.0

Resolution

Performance snapshots are continuous snapshots of proc nodes, collected at defined intervals for a specified period. Technical support may ask you to send performance snapshots to help troubleshoot a performance issue in response to a service request that you opened.

HTTP-based download of vm-support output from an ESXi:

Using any HTTP client:

https://ESXi_host_FQDN/cgi-bin/vm-support.cgi?performance=true&interval=5&duration=300

After the log bundle is collected and downloaded to a client, upload the logs to the SFTP/FTP site. For more information, see "Uploading Diagnostic information for VMware through the Secure FTP & Broadcom portal"

Command line based

To collect the performance snapshots, run this command:

• ESXi – vm-support -p

You may specify the collection duration and interval in seconds using these command-line options:

• ESXi – vm-support -p -d duration_in_seconds -i interval_in_seconds

To collect only performance snapshots from an ESXi host, run this command:

vm-support -p -a PerformanceSnapshot:vsi -d duration_in_seconds -i interval_in_seconds

If an interval is not specified, vm-support automatically sets the interval period to two times the amount of time taken to collect a single snapshot. For most cases, VMware recommends that you set the interval period to 10 seconds.

Note: To run the vm-support command, log in to your ESXi host with root privileges using the console or an SSH session.

The collected snapshots are bundled with regular data collected by vm-support and a tar archive is created in /var/tmp/esx-20##-01-26--20.46.3236587.tgz. To avoid space issues, the log files can be redirected to datastore by specifying the path.

• To redirect to a specified location include this parameter in the vm-support command: -w /vmfs/volumes/storage

If you want to collect only performance snapshots without the regular data, substitute the -s with an uppercase -S.

It is important that you use the vm-support script to capture performance snapshots when your system is experiencing a performance problem. The script cannot collect useful data otherwise. If the snapshot collection interval overlaps with a time when the virtual machine is not experiencing a performance problem, the result may skew the data collected and can make analysis difficult.

To download the vm-support script, see "Collecting diagnostic information for VMware ESXi". This article also contains related information about collecting debug information for ESXi systems.

For more information, see "Uploading Diagnostic information for VMware through the Secure FTP & Broadcom portal"

Additional Information

• For more information, see "Collecting performance data for ESXi hosts using the vSphere Client".
• In ESXi, run this command to collect only performance snapshots without logs:
  
  vm-support -p -a PerformanceSnapshot:vsi
  
   
• However, it is always desirable that the complete log bundle is collected with the performance snapshot