This issue is resolved in VMware ESXi 6.0, Patch Release ESXi600-201608001.

• When joined to an Active Directory (AD), ESXi host becomes unresponsive.
• ESXi hosts show as Not Responding in vCenter Server.
• The DCUI menu is slow to respond.
• Enabling services such as ESXi Shell or SSH may fail.
• In the /var/log/vmkernel.log file, you see entries similar to:
  
  ALERT: hostd detected to be non-responsive WARNING: UserParam: 1301: could not change group to <host/vim/vmvisor/hostd-probe>: Admission check failed for memory resource WARNING: LinuxFileDesc: 5637: Unrecoverable exec failure: Failure during exec while original state already lost
  
  Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.
• The ESXi hosts which are affected are all joined to Active Directory (AD) for Authentication Services.

• How to download patches in Customer Connect (1021623)
• VMware ESXi 6.0, Patch Release ESXi600-201608001 (2145663)