With VMware Host Client, you can use the advanced option Mem.MemEagerZero to determine how pages are zeroed out for virtual machines and user space applications.

To zero all pages when they allocated to virtual machines and user space applications, set Mem.MemEagerZero to one (1). If the memory is not reused, this setting prevents exposing the information from a virtual machine or user space applications to other clients while preserving the previous content in memory.

When you set Mem.MemEagerZero to 1, pages are zeroed when a user space application exits. For virtual machines, such pages are zeroed if:
  • The virtual machine is powered off.
  • The virtual machine pages are migrated.
  • The ESXi host reclaims virtual machines memory.
Note: For virtual machines, you can obtain this behaviour by setting the sched.mem.eagerZero advanced option to TRUE.

For information about setting the advanced virtual machine options, see the vSphere Resource Management documentation.

To configure the userworld memory zeroing, perform the following steps.


  1. Click Manage in the VMware Host Client inventory and click Advanced Settings.
  2. Enter Mem.MemEagerZero in the Search text box and click the Search icon.
  3. Right-click Mem.MemEagerZero and select Edit option from the drop-down menu.
    The Edit option dialog box opens.
  4. In the New value text box, enter the new value.

    The default value is zero (0).

  5. Click Save.
  6. (Optional) To reset the key setting to default, right-click the appropriate key from the list and select Reset to default.