VMware support has released an update (hot fix) that will resolve the PSOD issue with vShield 1.0 and ESX 4.1 U2. This hot fix needs to be installed manually instead of via the update manager.

To install the hot fix, do the following:

1. Enable SSH on the ESX host.
2. Copy the bundle to the ESX host (epsec-vfile.531366-release.zip) via wget or by using the datastore browser in the vSphere Client.
3. Put the host in maintenance mode. This may require powering off the VMs or migrating them to other hosts.
4. SSH into the ESX host and run the following commands:

   # vmkload_mod -u vfile
   # esxupdate --bundle epsec-vfile.531366-release.zip update

    

   Make sure to specify the full path to the epsec-vfile.531366-release.zip file.
5. Reboot the ESX host.
6. After the reboot, exit maintenance mode and resume using the ESX host.