{
  "slug": "tape-backhitch",
  "term": "Tape backhitch",
  "aliases": [
    "backhitch",
    "tape backhitching"
  ],
  "definition": "A tape backhitch stops and reverses the tape, then restarts it in the original direction to resume reading or writing at the required position.",
  "note": "During writing, an empty data buffer can require repositioning before recording resumes near the previous endpoint. Here, shoe-shining denotes repeated backhitching; vendor terminology also uses the expressions interchangeably. [ibm-control] [oracle-performance]\n\nRate mismatch is not the only trigger. Tape-mark and synchronization operations can cause backhitches. A position-control design also repositions after excessive head-position error interrupts writing. A backhitch alone therefore does not identify host starvation or damaged media. [oracle-sync] [ibm-position]\n\nSpeed matching addresses rate mismatch. It must not be confused with changing acknowledgement semantics: some Tape Application Accelerator modes buffer tape marks or replace synchronization commands with no-ops, requiring application-specific deferred-error handling. [oracle-sync]",
  "status": "shipping",
  "advantages": [],
  "limitations": [
    {
      "text": "Patent timing and wear statements describe examples or mechanisms, not a universal event duration or a measured field failure rate.",
      "citationIds": [
        "ibm-control",
        "ibm-position"
      ]
    }
  ],
  "related": [
    "tape",
    "lto",
    "tape-speed-matching",
    "tape-buffer-synchronization"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-28",
  "citations": [
    {
      "id": "ibm-control",
      "title": "Katagiri and Oe, US8035912B2: System and method for controlling traveling of tape, Background",
      "url": "https://patents.google.com/patent/US8035912B2/en",
      "accessed": "2026-10-27"
    },
    {
      "id": "ibm-position",
      "title": "Bui et al., US9251840B2: Dynamically controlling tape velocity, stop-write and repositioning description",
      "url": "https://patents.google.com/patent/US9251840B2/en",
      "accessed": "2026-10-27"
    },
    {
      "id": "oracle-sync",
      "title": "Oracle T10000 Systems Assurance Guide: File Sync Accelerator and Tape Application Accelerator",
      "url": "https://docs.oracle.com/cd/E48725_03/TTKSA/chapter1.htm",
      "accessed": "2026-10-27"
    },
    {
      "id": "oracle-performance",
      "title": "Oracle: Maximizing Tape Performance with the StorageTek T10000 Tape Drives, backhitching terminology",
      "url": "https://www.oracle.com/technetwork/server-storage/sun-tape-storage/documentation/o11-067-max-tape-perf-459638.pdf",
      "accessed": "2026-10-27"
    }
  ],
  "provenance": [
    "Source synthesis, not a drive experiment. No historical first-use date or wear-per-event estimate is assigned.",
    "The accelerator example is Oracle T10000 Tape Application Accelerator; its deferred-error contract is not a universal behavior of tape drives. [oracle-sync]"
  ]
}