{
  "slug": "nvme-available-spare",
  "term": "NVMe Available Spare",
  "aliases": [
    "Available Spare",
    "AVSP",
    "avail_spare"
  ],
  "definition": "NVMe Available Spare is the normalized percentage of spare capacity remaining in the NVM subsystem.",
  "note": "The SMART / Health Information log reports Available Spare at byte 3 and its threshold at byte 4, each on a 0-to-100 percentage scale. Critical Warning bit 0 indicates that spare capacity has fallen below the reported threshold; equality alone does not satisfy that condition. [nvme-base-2-3-smart]",
  "status": "shipping",
  "advantages": [],
  "limitations": [
    {
      "text": "Available Spare is not filesystem free space or the complement of Percentage Used; the two fields describe different quantities and need not change together.",
      "citationIds": [
        "microsoft-nvme-health",
        "nvme-base-2-3-smart"
      ]
    }
  ],
  "related": [
    "nvme-smart-log",
    "nvme-percentage-used",
    "nvme-critical-warning"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "microsoft-nvme-health",
      "title": "Microsoft: NVME_HEALTH_INFO_LOG, AvailableSpare and AvailableSpareThreshold members",
      "url": "https://learn.microsoft.com/en-us/windows/win32/api/nvme/ns-nvme-nvme_health_info_log",
      "accessed": "2026-10-14"
    },
    {
      "id": "nvme-base-2-3-smart",
      "title": "NVM Express Base Specification 2.3, section 5.2.12.1.3, Figure 210, p. 214: Available Spare and threshold",
      "url": "https://nvmexpress.org/wp-content/uploads/NVM-Express-Base-Specification-Revision-2.3-2025.08.01-Ratified.pdf",
      "accessed": "2026-10-14"
    }
  ],
  "updated": "2026-10-14"
}