hesela.devHost Protected Area (HPA)
A Host Protected Area is a region excluded from ordinary host reads and writes by an optional legacy ATA feature that lowers the device's maximum user-accessible address.
HPA changes the address limit reported to the host, not the partition table. The ATA/ATAPI-6 working draft describes reserving upper addresses for system data; it is historical evidence, not a current approved standard. [1]
This logical access restriction is distinct from SSD spare NAND and remapped pages. Removing it is not a sanitization operation. Accessible Max Address Configuration (AMAC) is a separate feature set. An HPA erase rule does not establish normal-mode ATA Security Erase coverage with AMAC. [2] [4]
In the ATA/ATAPI-6 draft, the SET MAX security extension uses a password separate from Security Mode. An accepted SET MAX FREEZE LOCK blocks subsequent SET MAX commands, including SET MAX UNLOCK, until a power cycle. It does not make accessible user data read-only or certify erased data. [1]
Relations
- related
- Device Configuration Overlay (DCO), Serial ATA (SATA), Data sanitization, Secure erase, Accessible Max Address Configuration (AMAC)
Limitations
- A whole-device host overwrite still cannot address a region excluded by the active HPA limit. [1]
Citations
- T13 ATA/ATAPI-6 working draft 1410D revision 3a (2001), sections 6.15 and 6.21; historical draft, not an approved standard
- Seagate openSeaChest maintainer clarification (7 January 2021), discussion 52: HPA/DCO versus AMAC erase scope
- Seagate openSeaChest ATA Security Feature guide (last edited 11 February 2026), Security Erase