This article describes support of the Thunderbolt interface with Symantec Encryption Desktop on Mac OS X.
When using Symantec Encryption Desktop, you are unable to access an encrypted (formerly PGP Whole Disk Encryption) disk connected to a MacBook via a Thunderbolt interface. However, diskutil displays it as plugged in to the system. In some cases if may even freeze the host system that the target machine is attached to.
Symantec Drive Encryption (formerly PGP Whole Disk Encryption) is only compatible with the devices connected over the Thunderbolt interface to Mac OS X 10.8.4 and newer systems.
Apple released the Mac OS X update to version 10.8.4 which appears to have resolved the issue. If you are facing this problem please update your version of Mac OS X to 10.8.4 or newer or see if the workaround below can be applied.
As a workaround, use another interface available on the device and connect it to the Mac OS X system using FireWire.
Note: Target Disk Mode is not supported via USB on a Mac
This Feature Request is available in the following release: