hesela.devDevice Configuration Overlay (DCO)
Device Configuration Overlay is an optional legacy ATA mechanism that can reduce a device's reported capacity and available features.
DCO is a device configuration mechanism, not a partition. The documented drive implementation changes reported features and capacity, including the result of READ NATIVE MAX ADDRESS. That result alone therefore need not reveal the unrestricted capacity. [1]
Removing a capacity restriction is not evidence that data was erased. Do not assume all device erase operations have the same scope: the openSeaChest maintainer distinguishes normal ATA Security Erase from enhanced erase and Sanitize for HPA/DCO. This is a command-scope clarification, not testing of an individual drive. [2]
In the ATA/ATAPI-6 draft, an accepted DEVICE CONFIGURATION FREEZE LOCK blocks configuration changes and DEVICE CONFIGURATION IDENTIFY until power-down; hardware and software resets do not clear it. An aborted identification request alone does not prove DCO is unsupported. [5]
Relations
- related
- Host Protected Area (HPA), Serial ATA (SATA), Data sanitization, Secure erase, Accessible Max Address Configuration (AMAC)
Limitations
- Device support and sanitization coverage require device-specific evidence; a feature label does not certify a successful erase. [3]
Citations
- Seagate Laptop HDD Product Manual 100772113 Rev. C (2016), section 11.2.3: DCO capacity and READ NATIVE MAX
- Seagate openSeaChest maintainer clarification (7 January 2021), discussion 52: HPA/DCO versus AMAC erase scope
- NIST SP 800-88 Rev. 2 (2025), Appendix B: device-specific sanitization implementation and uncovered areas
- T13 ATA/ATAPI-6 working draft 1410D rev. 3a (2001), sections 8.8.2.8 and 8.8.3.6: DCO freeze and identification