Symantec Drive Encryption includes support for dual-boot operating system environment
Symantec Drive Encryption
The Symantec Drive Encryption feature is available for use on dual-boot systems as long as you boot to an operating system supported by Symantec Drive Encryption. The currently supported operating systems include Windows 7/8/10 Ubuntu and Redhat Linux.
See the Release Notes for compatible Linux systems for these dual-boot scenarios:
Symantec Encryption Desktop 10.3:
Symantec Encryption Desktop 10.3.2 for Windows Release Notes
Symantec Drive Encryption 10.3.2 for Linux Release Notes
Symantec Encryption Desktop 10.4:
Symantec Encryption Desktop 10.4.x for Windows Release Notes
Symantec Drive Encryption 10.4.x for Linux Release Notes
Note: Symantec Drive Encryption is supported only on dual-boot systems on a single hard disk. Performing encryption on two separate hard disks is not supported. Symantec Encryption Desktop must be installed on both operating systems before encrypting the disk.
Warning: Do not use Symantec Drive Encryption to encrypt server hardware, this scenario is tested for non-server operating systems.
Partition Encryption
Be aware when using Partition mode encryption, this mode only supports dual-booting with another operating system (such as Linux) as long as you encrypt only the Windows partition. The unsupported operating system must be on separate non-encrypted partition. If encrypting both OS partitions is desired, Full Disk encryption mode must be used instead of Partition mode.
For a common dual-boot-environment with Windows and Linux, install them as usual - Windows first and then Linux afterwards. You can install grub in the MBR of the system disk, typically /dev/sda. When using a version of Linux that is not supported by Symantec Encryption Desktop, you have to only encrypt the Windows partition. When you boot, the bootguard will come up and you can authenticate. Grub will be loaded with the usual menu and you can load the encrypted Windows or the other, non-encrypted operating system.
Note: For additional information on partition encryption, please read the article at the following link. Partition encryption for Windows