Quoting TechTarget - SearchServerVirtualization

The third installment of the article from David Marshall and Wade Reynolds:

Everyone can use a performance boost, and even an enterprise-grade virtualization package like VMware ESX Server is no exception. Careful tweaks can bring big performance gains for your virtual environment.

In this series, we've discussed numerous ways in which you can boost your ESX Server environment's performance, ranging from storage to remote access to VM-to-host ratios. In this part, we'll look at updating your VMware tools, optimizing your guest operating systems and evaluating your antivirus tools and backup strategy.

Tip 9: Update VMware Tools

As you upgrade your ESX Server versions and/or install update patches, be sure to keep VMware Tools installed in your guest operating systems up-to-date. Sometimes, update patches may include fixes for components of VMware Tools, and in these cases, it is very important to update VMware Tools in your virtual machines.

If you migrate virtual machines from other VMware platforms such as VMware Workstation or VMware Server, be sure to update VMware Tools after migrating the virtual machine. There are differences in the editions of VMware Tools between the different VMware products.

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Read the rest of the article, here.