{
  "slug": "host-aware-smr",
  "term": "Host-aware SMR",
  "aliases": [
    "HA-SMR",
    "host-aware shingled magnetic recording"
  ],
  "definition": "A historical SMR disk interface that exposes zone information while accepting non-sequential writes in sequential-write-preferred zones.",
  "note": "Write model: Unlike host-managed SMR, host-aware disks accept random writes and remain usable as regular disks. Their sequential-write-preferred zones are distinct from host-managed sequential-write-required zones; conventional zones are optional in both models. [c1]\n\nOpen zones: An advertised optimal open-zone count is a performance guideline rather than an enforced limit. Sequential placement can avoid work caused by non-sequential writes, but compatibility alone gives no workload latency guarantee. [c1]\n\nLinux support: Upstream Linux 6.8 removed the host-aware block-layer model while retaining ordinary block-device access. Do not expect queue/zoned to report host-aware; none does not establish CMR recording. This is distinct from device identification and command passthrough. [c3]\n\nEvidence scope: Wu et al. studied ST8000AS0022 drives with prototype firmware ZN03 in 2016. Bursty sequential writes and sustained non-sequential writes exposed different bottlenecks. Their 128-open-zone recommendation is device-specific, not an HA-SMR interface limit. [c4]",
  "status": "research",
  "advantages": [
    {
      "text": "The historical device interface permits zone-aware placement while accepting ordinary random writes; host software support is a separate requirement.",
      "citationIds": [
        "c2"
      ]
    }
  ],
  "limitations": [
    {
      "text": "A SATA disk behind a SAS HBA needs compatible command translation to use its zone-management commands.",
      "citationIds": [
        "c2"
      ]
    }
  ],
  "related": [
    "hm-smr",
    "device-managed-smr",
    "smr",
    "zbc",
    "zac",
    "zoned-block-device"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "c1",
      "title": "Zoned Storage: SMR interface models, zone types and limits",
      "url": "https://zonedstorage.io/docs/introduction/smr",
      "accessed": "2026-10-18"
    },
    {
      "id": "c2",
      "title": "Zoned Storage: host-aware SMR and HBA compatibility",
      "url": "https://zonedstorage.io/docs/getting-started/smr-disk",
      "accessed": "2026-10-18"
    },
    {
      "id": "c3",
      "title": "Linux commit 7437bb73f087: remove the host-aware block-layer model",
      "url": "https://github.com/torvalds/linux/commit/7437bb73f087e5f216f9c6603f5149d354e315af",
      "accessed": "2026-10-18"
    },
    {
      "id": "c4",
      "title": "Wu et al., Evaluating Host Aware SMR Drives, HotStorage 2016, sections 3.1-3.3",
      "url": "https://www.usenix.org/system/files/conference/hotstorage16/hotstorage16_wu.pdf",
      "accessed": "2026-10-18"
    }
  ],
  "provenance": [
    "Historical prototype interface; status research records that evidence, not current product availability. Linux behavior is qualified by the upstream removal commit; distributions may carry different patches.",
    "The 2016 paper is a source review, not a reproduced experiment or a performance claim for other drives."
  ],
  "updated": "2026-10-18"
}