User Manual

Enterprise Self-Encrypting Drive User’s Guide, Rev. B 21
4.0 User data bands
Unlike a standard drive, the user data area can be divided into separate data bands, each with its own password
(BandMasterX) and set of locking parameters. The number of data bands available is product dependent but is never
less than two.
When the drive leaves the factory all of its data bands are available but only band 0 is allocated. Band 0 is also known
as the global band. The global band starts at LBA(0) and continues through LBA (max). In other words, at the time of
shipment, the global band occupies the entire surface of the media minus the area allocated to the system band at
the disk’s inner radius. To allocate a data band to a physical address space on the disk, we need to know two things:
• The LBA that identifies the start of the band
• The number of LBAs contained in the band (the range)
If a band has not been allocated, the range is set to zero signifying that it does not provide any storage space. So let’s
go ahead and create a drive with the three data bands shown in Figure 13.
Figure 13. A disk with 100 LBAs and three data bands
For the sake of simplicity, let’s say we have a total of 100 LBAs on the disk. The global band (band 0) will therefore start
at LBA 0 and end at LBA 99.
To allocate band 1, we will set the start address to LBA 16 and the range to 24
To allocate band 2, we will set the start address to LBA 56 and the range to 8.