
Ultrastar 7K2
HGST Hard Disk Drive Technical Reference Manual
26
48-bit Logical Block Addressing (LBA)
The 48-bit Address feature set allows devices with capacities up to approximately 281 tera sectors or
approximately 144 peta bytes. In addition, the number of sectors that may be transferred by a single
command are increased by increasing the allowable sector count to 16 bits.
48-bit Address
Bits (47:40)
Bits (39:32)
Bits (31:24)
Bits (23:16)
Bits (15:8)
Bits (7:0)
LBA High (exp)
LBA Mid (exp)
LBA Low (exp)
LBA High
LBA Mid
LBA Low
16-bit Sector Count
Bits (15:8)
Bits (7:0)
Sector Count (exp)
Sector Count
Self-Monitoring, Analysis, and Reporting Technology
(S.M.A.R.T.)
S.M.A.R.T. helps you monitor a drive’s internal status through diagnostic commands at the host level.
The drive monitors Read Error Rate, Start/Stop Count, Re-allocated Sector Count, Seek Error Rate,
Power-on Hours Count, Spin-up Retry Count, Drive Calibration Retry Count, Drive Power Cycle Count,
Offline Scan Uncorrectable Sector Count, Ultra ATA CRC Error Rate, Multi-zone Error Rate, Spin-up
Time, Relocation Event Count, and Current Pending Sector Count. The hard drive updates and stores
these attributes in the reserved area of the disk. The drive also stores a set of attribute thresholds that
correspond to the calculated attribute values. Each attribute threshold indicates the point at which its
corresponding attribute value achieves a negative reliability status.