Figure 6-23 Actions menu in Volumes by pool For more information about CLI commands for migrating volumes to and from child pools, see  Chapter 7, “Volumes” on page 263. IBM SAN Volume Controller supports two types of encryption: hardware and software. Hardware encryption is implemented at an array level; software encryption is implemented at  a storage pool level. For more information about encryption and encrypted storage pools, see  Chapter 12, “Encryption” on page 629. In IBM Spectrum Virtualize terminology, external storage systems that provide resources to  be used as MDisks are called  Controllers . IBM SAN Volume Controller supports external  storage controllers that are attached through iSCSI and Fibre Channel (FC). FC and iSCSI storage controllers can be managed through the External Storage pane. To  access the External Storage pane, click  Pools  External Storage , as shown in Figure 6-24. Figure 6-24 External Storage pane Chapter 6. Storage pools  229 6.2.1 External storage controllers 6.2 Working with external controllers and MDisks 6.1.5 Encrypted storage pools