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SMART Attribute Name Variants Across Drive Manufacturers

Project: SMART Sniffer Author: Research compiled March 2026 Purpose: Documents the manufacturer-specific SMART attribute names used in smartctl --json output, informing the ata_name_map in sensor.py.

Background

When smartctl reads a drive's SMART attribute table, it translates raw attribute IDs into human-readable names using its built-in drivedb.h database. The name strings it produces vary significantly between manufacturers — sometimes even between product lines from the same manufacturer. This is a real-world interoperability problem: two drives reporting the same physical measurement (e.g. temperature, wear level) may use entirely different name strings in their JSON output.

SMART Sniffer's sensor.py maps each logical sensor key (e.g. wear_leveling_count) to a list of known attribute name strings. This document records all known variants, their sources, and any gaps still requiring verification.

Attribute Coverage by Manufacturer

The table below summarises which manufacturers have been confirmed for each of the five monitored attributes. ✅ = confirmed name known, ⚠️ = partially confirmed or needs verification, — = attribute not applicable to this drive type.

Manufacturer Temp Power-On Hours Reallocated Sectors Pending Sectors Uncorrectable Errors Wear Leveling
Seagate (HDD) ✅ ✅ ✅ ✅ ✅ —
Western Digital (HDD) ✅ ✅ ✅ ✅ ✅ —
Toshiba (HDD) ✅ ✅ ✅ ✅ ✅ —
HGST / Hitachi (HDD) ✅ ✅ ✅ ✅ ✅ —
Samsung (SSD) ✅ ✅ ✅ ✅ ✅ ✅
Intel (SSD) ✅ ✅ ✅ ✅ — ✅
Crucial / Micron ✅ ✅ ✅ ✅ — ✅
Kingston ✅ ✅ ✅ ✅ — ✅
SanDisk / WD (SSD) ✅ ✅ ✅ ✅ — ✅
SK Hynix (SSD) ✅ ✅ ✅ ✅ — ⚠️
NVMe (all) ✅ ✅ — — ✅ (media_errors) ✅ (% used)

Attribute Details

1. Temperature

Logical key: temperature Unit: °C ATA attribute IDs typically used: 190, 194

Name String Manufacturers / Notes
Temperature_Celsius Most HDDs: Seagate, WD, Toshiba, HGST, Hitachi (ID 194)
Temperature_Internal Some Intel SSDs (ID 194)
Airflow_Temperature_Cel Samsung SSDs (ID 190), some Intel SSDs (also ID 190)
HDA_Temperature Older Hitachi and HGST HDDs (ID 194)
Drive_Temperature Some generic and OEM drives

NVMe path: nvme_smart_health_information_log.temperature

Note: Samsung SSDs report temperature on ID 190 (Airflow_Temperature_Cel) rather than the more common ID 194. ID 190 measures the airflow temperature near the controller, which is functionally the same reading for monitoring purposes.

2. Power-On Hours

Logical key: power_on_hours Unit: hours ATA attribute ID: 9

Name String Manufacturers / Notes
Power_On_Hours Most manufacturers — highly standardised
Power_On_Hours_and_Msec Some Western Digital drives
Power_On_Time Some older drives, generic OEM firmware

NVMe path: nvme_smart_health_information_log.power_on_hours

Note: Power_On_Hours_and_Msec encodes both hours and milliseconds in the raw value. smartctl extracts only the hours component in the raw.value field, so the mapping works correctly without special-casing.

3. Reallocated Sector Count

Logical key: reallocated_sector_count ATA attribute ID: 5 Applicability: ATA/SATA only (not NVMe)

Name String Manufacturers / Notes
Reallocated_Sector_Ct Virtually all manufacturers — one of the most standardised SMART attributes

Note: This is the most consistent attribute name across the entire SMART ecosystem. The short form _Ct (not _Count) is the standard in smartctl's drivedb. There are no known meaningful variants in active use.

4. Current Pending Sector Count

Logical key: current_pending_sector_count ATA attribute ID: 197 Applicability: ATA/SATA only (not NVMe)

Name String Manufacturers / Notes
Current_Pending_Sector Most manufacturers (Seagate, Toshiba, HGST, Samsung)
Current_Pending_Sector_Ct Some Western Digital and HGST variants
Total_Pending_Sectors Some Micron and Crucial SSDs

Note: A non-zero value here means sectors the drive has identified as potentially unreadable and is waiting to reallocate. Elevated counts warrant monitoring and imminent backup.

5. Reported Uncorrectable Errors

Logical key: reported_uncorrectable_errors ATA attribute IDs used: 187 (uncorrectable errors count), 198 (offline uncorrectable) Applicability: ATA/SATA primarily; NVMe uses media_errors

Name String Manufacturers / Notes
Offline_Uncorrectable Most HDDs: Seagate, WD, Toshiba, HGST (ID 198)
Reported_Uncorrect Some Seagate and WD variants
Uncorrectable_Error_Cnt Samsung SSDs (ID 187) — semantically equivalent
Total_Offl_Uncorrectabl Some Hitachi and HGST HDDs

NVMe path: nvme_smart_health_information_log.media_errors

Note: IDs 187 and 198 measure slightly different things (ECC errors vs. offline surface scan errors), but both indicate unrecoverable data integrity issues and are treated as equivalent for alerting purposes. A healthy drive should show 0 for all variants.

6. Wear Leveling / SSD Endurance

Logical key: wear_leveling_count Unit: % used (0% = new, 100% = fully worn -- normalized from ATA's inverted scale) Applicability: SSDs only (ATA/SATA); NVMe uses a dedicated field

Name String Manufacturers / Notes
Wear_Leveling_Count Samsung SSDs (ID 177) — 870 EVO, 860, 860 EVO, 850 Pro/EVO, etc. Reports remaining erase cycles (higher = newer)
Wear_Range_Delta Some Samsung SSD variants
Media_Wearout_Indicator Intel SSDs (ID 233), some WD/SanDisk SSDs. 100 = new, 0 = worn out
SSD_Life_Left Intel 520, 530 series; some Kingston SSDs (ID 231)
Remaining_Lifetime_Perc Kingston SSDs (ID 231)
Percent_Lifetime_Remain Crucial/Micron SSDs (ID 202)
Perc_Rated_Life_Remain Some Micron enterprise SSD variants
Percent_Life_Remaining Some SanDisk SSDs
Drive_Life_Protection_Stat Some WD Blue SSDs (ID 230)

NVMe path: nvme_smart_health_information_log.percentage_used (0% = new, 100% = fully worn)

ATA wear normalization (v0.5.6+): ATA drives report the normalized VALUE column as "percentage of life remaining" (100 = new, 0 = worn). SMART Sniffer inverts this to "percentage used" (0 = new, 100 = worn) for consistency with NVMe percentage_used semantics. The raw value is vendor-specific (erase cycles, write counts, etc.) and is not used.

TODO: SK Hynix SSDs are believed to use ID 177 for wear leveling (same as Samsung), but the exact attribute name string in smartctl's drivedb has not been confirmed. Verification needed via smartctl -a output on an SK Hynix drive.

NVMe Summary

NVMe drives use a completely different data structure: nvme_smart_health_information_log (a flat dict) rather than the ATA attribute table. The mappings are:

Logical Key NVMe JSON Field Notes
temperature temperature Always present
power_on_hours power_on_hours Always present
wear_leveling_count percentage_used 0 = new, 100 = fully worn (inverted vs. some ATA SSDs)
reported_uncorrectable_errors media_errors Cumulative unrecoverable media errors
reallocated_sector_count N/A Not applicable to NVMe — entity not created
current_pending_sector_count N/A Not applicable to NVMe — entity not created

Sources and References

  • smartmontools drivedb.h — Primary source for attribute ID-to-name mappings: https://github.com/smartmontools/smartmontools/blob/master/smartmontools/drivedb.h
  • Backblaze Hard Drive Stats — Real-world validation of attribute names across drive populations: https://www.backblaze.com/b2/hard-drive-test-data.html
  • Kingston SSD SMART Attribute Reference — Internal document referenced in community forums; confirms SSD_Life_Left and Remaining_Lifetime_Perc for ID 231
  • Samsung SSD datasheet notes — ID 177 (Wear_Leveling_Count) semantics confirmed via Samsung 870 EVO product documentation
  • Intel SSD product spec sheets — ID 233 (Media_Wearout_Indicator) and ID 231 (SSD_Life_Left) confirmed for Intel 520/530 series
  • smartctl community reports (SmallNetBuilder, TrueNAS forums, r/DataHoarder) — Supplemental validation for less common variants
  • Direct observation — Samsung 870 EVO 500GB, Samsung 860 EVO 1TB on Proxmox test system (March 2026)

Open Questions

  1. SK Hynix wear leveling: Attribute ID 177 is expected but the exact name string in smartctl output has not been confirmed. A sample smartctl -a /dev/sdX from an SK Hynix SSD is needed.
  2. SAS/SCSI drives: Not covered. These use an entirely different SMART data structure in smartctl JSON output — a future sensor.py extension will be needed.
  3. Western Digital Blue/Green SSDs: Some models report via the ATA attribute table differently than WD Black/Red HDDs. Drive_Life_Protection_Stat (ID 230) is confirmed for WD Blue SSDs but coverage is not exhaustive.
  4. Seagate Barracuda SSDs: Seagate's SSD lineup uses attribute names inherited from their HDD firmware team — confirmation that all HDD names listed here apply equally to their SSDs is pending.