{
  "slug": "additional-sense-code",
  "term": "Additional sense code",
  "aliases": [
    "ASC",
    "SCSI ASC"
  ],
  "definition": "The additional sense code (ASC) is an eight-bit SCSI sense-data field that refines the sense key and is interpreted together with its qualifier.",
  "note": "Use the ASC and ASCQ as a pair and check the device-type applicability in T10's assignments. The lookup table is informative; the applicable written standard takes precedence. [t10-asc] Missing bytes in a truncated report must not be treated as an observed 00h/00h pair. [linux-sense] Software translation can be version-dependent: Linux v6.12 maps BSY to 0Bh/47h/00h, whereas the pinned 3857c2fe5449 routine maps it to 0Bh/00h/00h. Both ignore the ATA error byte when BSY is set. Keep the kernel version and original registers; a translated code is not a unique physical diagnosis. [linux-v612-ata] [linux-pinned-ata]",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "scsi",
    "scsi-check-condition",
    "scsi-sense-key",
    "additional-sense-code-qualifier"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-13",
  "citations": [
    {
      "id": "t10-asc",
      "title": "T10: Additional sense data and ASC/ASCQ lookup tables",
      "url": "https://www.t10.org/lists/2asc.htm",
      "accessed": "2026-10-13"
    },
    {
      "id": "linux-sense",
      "title": "Linux v6.12: scsi_normalize_sense, fixed and descriptor field extraction",
      "url": "https://github.com/torvalds/linux/blob/v6.12/drivers/scsi/scsi_common.c",
      "accessed": "2026-10-13"
    },
    {
      "id": "hesela-sense",
      "title": "Media error or link error? SCSI sense codes and Linux ATA logs",
      "url": "https://hesela.com/analyses/scsi-sense-kernel-log-signatures/",
      "accessed": "2026-10-13"
    },
    {
      "id": "linux-pinned-ata",
      "title": "Linux pinned 3857c2fe5449: ata_to_sense_error and its callers",
      "url": "https://github.com/torvalds/linux/blob/3857c2fe5449541e24afc5efdb0f81a8a8f9a3a0/drivers/ata/libata-scsi.c",
      "accessed": "2026-10-13"
    },
    {
      "id": "linux-v612-ata",
      "title": "Linux v6.12, commit adc218676eef: ATA-to-SCSI translation",
      "url": "https://github.com/torvalds/linux/blob/adc218676eef25575469234709c2d87185ca223a/drivers/ata/libata-scsi.c",
      "accessed": "2026-10-13"
    }
  ]
}