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.
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.
When deploying virtual machines located on a non-shared storage to other ESXi hosts, the deployment occurs across the network (using NFC/hostd). This may have an impact on the file system buffer cache and exhaust the number of buffers, reporting a significant delay in deployment time.
> Login to the host console using ‘root’ credentials
>Click on Manage
>From System Tab please click on ‘Advanced Settings’
To prevent this issue, relocate the virtual machine templates to a shared storage that is presented to all ESXi hosts.
- To increase the number of buffers from 2048 to 4096, run this command:# esxcfg-advcfg -s 32768 /BufferCache/MaxCapacity
Note: If the above change does not result in a significant improvement, try reducing the flush interval.
- To reduce the Buffer Cache Flush interval from 30 seconds to 20 seconds, run this command:# esxcfg-advcfg -s 20000 /BufferCache/FlushInterval
A host reboot is not required to increase the buffers, but to decrease the buffers to a lower value or to the default value, a host reboot is necessary for the changes to take effect.