hesela.devTape backhitch
A tape backhitch stops and reverses the tape, then restarts it in the original direction to resume reading or writing at the required position.
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. [1] [4]
Rate 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. [3] [2]
Speed 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. [3]
Relations
- related
- Magnetic tape storage, LTO (Linear Tape-Open), Tape speed matching, Tape buffer synchronization
Limitations
- Patent timing and wear statements describe examples or mechanisms, not a universal event duration or a measured field failure rate. [1, 2]
Citations
- Katagiri and Oe, US8035912B2: System and method for controlling traveling of tape, Background
- Bui et al., US9251840B2: Dynamically controlling tape velocity, stop-write and repositioning description
- Oracle T10000 Systems Assurance Guide: File Sync Accelerator and Tape Application Accelerator
- Oracle: Maximizing Tape Performance with the StorageTek T10000 Tape Drives, backhitching terminology
Sources & caveats
- 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. [3]