{
  "slug": "scsi-unit-serial-number",
  "term": "SCSI Unit Serial Number",
  "aliases": [
    "Unit Serial Number VPD page",
    "SCSI VPD 0x80",
    "VPD page 80h"
  ],
  "definition": "The SCSI Unit Serial Number VPD page 0x80 reports a vendor-assigned product serial number for the addressed target or logical unit.",
  "note": "The serial uses a vendor-defined format; it is not the typed descriptor list returned by Device Identification page 0x83. Keep vendor and product context with it when comparing device inventories. [sdparm-vpd] [seagate-scsi]\n\nA host property named ID_SERIAL need not be the raw page-0x80 value. By default, systemd v257 scsi_id prefers supported page-0x83 identifiers; its page-0x80 path constructs a string from an S prefix, vendor, model and serial. A derived host identifier and the reported serial therefore need separate labels in an evidence record. [systemd-scsi-id] [systemd-scsi-export]",
  "related": [
    "scsi-logical-unit",
    "scsi-device-identification",
    "multipath-io"
  ],
  "citations": [
    {
      "id": "sdparm-vpd",
      "title": "Douglas Gilbert: sdparm 1.12 documentation, VPD pages and descriptor associations",
      "url": "https://doug-gilbert.github.io/sdparm.html",
      "accessed": "2026-11-03"
    },
    {
      "id": "seagate-scsi",
      "title": "Seagate SCSI Commands Reference Manual, 100293068 Rev. L (November 2020), sections 5.4.9 and 5.4.22",
      "url": "https://www.seagate.com/files/staticfiles/support/docs/manual/Interface%20manuals/100293068L.pdf",
      "accessed": "2026-11-03"
    },
    {
      "id": "systemd-scsi-id",
      "title": "systemd v257: scsi_serial.c, check_fill_0x83_id, do_scsi_page80_inquiry and scsi_get_serial",
      "url": "https://raw.githubusercontent.com/systemd/systemd/v257/src/udev/scsi_id/scsi_serial.c",
      "accessed": "2026-11-03"
    },
    {
      "id": "systemd-scsi-export",
      "title": "systemd v257: scsi_id.c, sanitized ID_SERIAL and ID_SERIAL_SHORT exports",
      "url": "https://raw.githubusercontent.com/systemd/systemd/v257/src/udev/scsi_id/scsi_id.c",
      "accessed": "2026-11-03"
    }
  ],
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-03",
  "provenance": [
    "Primary documentation and pinned implementation review on 2026-11-03; no device interrogation, failover experiment or global-uniqueness measurement."
  ]
}