VMware ESXi and ESX provide advanced configuration options that affect the behavior of various components. This article provides steps to review and set new advanced configuration options using several methods. VMware recommends that you set these configuration options under the direction of VMware Technical Support or a VMware Knowledge Base article.

Numeric options have limited ranges (for example, 0-10). String options accept any value. Option values are not checked for validity beyond being in the proper range. Confirm all changes before applying them.

Caution: Some configuration options take effect immediately, whereas others require a reboot before taking effect. The impact of changing specific options is outside the scope of this article.

Also see: New Kernel options available on ESXi 7.0

Advanced configuration settings can be reviewed and modified on an ESXi/ESX host using the vSphere Web Client, vSphere Client, PowerCLI, Command-Line Interface, or local console.

All options are grouped into sections. A given method may visually group the sections or separate the section and option names using a forward slash or period. Options are usually documented using the form SectionName.OptionName.

Setting advanced configuration options using the vSphere Web Client for ESXi 5.1/5.5/6.x

The vSphere Web Client lists advanced configuration options

To set advanced configuration settings using the vSphere Web Client:

1. Connect to the vCenter Server using the vSphere Web Client.
2. Select an ESXi host in the inventory.
3. Click the Manage tab.
4. Click the Settings sub-tab.
5. Under the System heading, click Advanced System Settings. Settings are listed alphabetically by name similar to SectionName.OptionName.
6. (Optional) Click in the Filter box and search for an setting name.
7. Select the setting by name from the list.
8. Click the Edit pencil icon.
9. Change the configuration option to the desired new value.
10. Click OK to accept the changes.
    
    Note: If an out-of-range value is specified, the vSphere Web Client indicates this with a red highlight around the new value.
     

Setting advanced configuration options using the vSphere Client for ESXi/ESX 3.0. 4.x, 5.x and 6.x

The vSphere Client lists configuration options grouped by sections on the left. The options list is not sorted.

To set advanced configuration options using the vSphere Client:

1. Connect to the vCenter Server or the ESXi/ESX host using the vSphere Client.
2. Select the ESXi/ESX host in the Inventory.
3. Click the Configuration tab.
4. Under the Software heading, click Advanced Settings.
5. Select the section on the left corresponding the option's section name.
6. Locate the option name in the list on the right, these names are usually similar to SectionName.OptionName.
7. Specify a new value for setting.
8. Click OK to accept the changes.
   
   Note: If an out-of-range value is specified, the vSphere Client reports the error: The value entered is not valid. Enter another value.

Setting advanced configuration options using the vSphere PowerCLI

The VMware vSphere PowerCLI is a powerful command-line tool used to automate aspects of vSphere management. PowerCLI is distributed as a Windows PowerShell snapin. Commands can be run directly against an ESXi/ESX host, or target any ESXi/ESX host that vCenter Server manages. Section and option names are separated by a period.

For more information on usage, see the vSphere PowerCLI documentation.

To set advanced configuration options using the vSphere PowerCLI:

1. Open a command prompt at the location where vSphere PowerCLI is installed.
2. Connect to the ESXi/ESX host using the command:
   
   Connect-VIServer ESXHostnameOrIP
    
3. Check the current value of an option using the Get-VMHostAdvancedConfiguration command:
   
   Get-VMHostAdvancedConfiguration -Name "SectionName.OptionName"
   
   For example:
   
   Name Value
---- -----
SectionName.OptionName CurrentValue
    
4. Specify a new value for an option using the Set-VMHostAdvancedConfiguration command:
   
   Set-VMHostAdvancedConfiguration -Name "SectionName.OptionName" -Value "NewValue"
   
   Note: If an out-of-range value is specified, the command fails with the fault: A specified parameter was not correct.

Setting advanced configuration options using esxcli for ESXi 5.x and 6.x

The VMware vSphere ESX Command-Line Interface (esxcli) is use to run common system administration commands against ESXi hosts from any client with network access to those systems, or from the local ESXi host console. To set advanced configuration options using esxcli:

1. Open a console at the location where esxcli is installed. For more information, see the VMware vSphere Command Line Interface documentation.
2. Check the current value of an option using the esxcli command:
    
   • For runtime options:
     
     esxcli system settings advanced list -o "/SectionName/OptionName"
      
   • For boot-time options in the VMkernel.boot.* namespace:
     
     esxcli system settings kernel list -o "OptionName"
      
   You see output similar to:
   
   Path: /SectionName/OptionName
Type: integer
Int Value: n
Default Int Value: 5
Min Value: 0
Max Value: 10
String Value:
Default String Value:
Valid Characters:
Description: Description of OptionName
    
3. Specify a new value for an option using the esxcli command:
    
   • For runtime options:
     
     esxcli system settings advanced set -o "/SectionName/OptionName" [--int-value|--string-value] "NewValue"
      
   • For boot-time options in the VMkernel.boot.* namespace:
     
     esxcli system settings kernel set -o "OptionName" [--int-value|--string-value] "NewValue"
     
     Note: If an out-of-range value is specified, the command fails with the fault: Sysinfo error on operation returned status : Bad parameter.

Setting advanced configuration options using the vSphere Command-Line Interface in ESXi/ESX 3.x and 4.x

The VMware vSphere Command-Line Interface (vCLI) is used to run common system administration commands against ESXi/ESX hosts from any client with network access to those systems. Commands can be run directly against an ESXi/ESX host, or target any ESXi/ESX host that vCenter Server manages. Section and option names are separated by a period.

For more information on usage, see the vSphere Command-Line Interface Documentation.

To set advanced configuration options using the vCLI:

1. Open a command prompt at the location where the vCLI is installed.
2. Check the current value of an option using the vicfg-advcfg.pl command:
    
   • For runtime options:
     
     vicfg-advcfg.pl <connection options> --get SectionName.OptionName
      
   • For boot-time options in the VMkernel.boot.* namespace:
     
     vicfg-advcfg.pl <connection options> --get-kernel OptionName
      
   You see output similar to:
   
   Value of SectionName.OptionName is X
    
3. Set a new value for an option using the vicfg-advcfg.pl command:
    
   • For runtime options:
     
     vicfg-advcfg.pl <connection options> --set "NewValue" SectionName.OptionName
      
   • For boot-time options in the VMkernel.boot.* namespace:
     
     vicfg-advcfg.pl <connection options> --set-kernel "NewValue" OptionName
      
   Note: If an out-of-range value is specified, the command fails with the fault: A specified parameter was not correct.

Setting advanced configuration options using the local console in ESXi/ESX 3.x and 4.x

The local console of the ESXi/ESX host can be used to run common system administration commands if network connectivity is not available. The other methods are preferred. Section and option names are separated by a forward slash.

To set advanced configuration options using the local console:

1. Open a console to the ESXi or ESX host. For more information, see Unable to connect to an ESX host using Secure Shell (SSH) (1003807) or Using Tech Support Mode in ESXi 4.1 (1017910).
2. Check the current value of an option using the esxcfg-advcfg command:
    
   • For runtime options:
     
     esxcfg-advcfg --get /SectionName/OptionName
      
   • For boot-time options in the VMkernel.boot.* namespace:
     
     esxcfg-advcfg --get-kernel OptionName
   
   For example:
   
   Value of SectionName.OptionName is X
    
3. Set a new value for an option using the esxcfg-advcfg command:
    
   • For runtime options:
     
     esxcfg-advcfg --set "NewValue" /SectionName/OptionName
      
   • For boot-time options in the VMkernel.boot.* namespace:
     
     esxcfg-advcfg --set-kernel "NewValue" OptionName
   
   Note: If an out-of-range value is specified, the command fails with the error: A specified parameter was not correct.