Tape-creep detection via trajectory and distortion angles
A tape drive may calculate the slopes for three successive timing-based-servo marks in a timing-based-servo group. The timing-based-servo marks may be arranged in a one or more M-patterns. The three successive timing-based-servo marks may be across the one or more M-patterns. The tape drive may perform a parabolic fit of a gradient of the slopes. The tape drive may determine whether the gradient is demonstrative of tape-creep.
1. A method for allowing a tape drive to write to a tape cartridge with timing-based-servo marks, the method comprising:
calculating slopes for three successive timing-based-servo marks in a timing-based-servo group, wherein the timing-based-servo marks are arranged in one or more M-patterns, and wherein the three successive timing-based-servo marks are across the one or more M-patterns;
performing a parabolic fit of a gradient of the slopes;
determining whether the gradient is demonstrative of tape-creep; and
writing, from the tape drive, to the tape cartridge.
2. The method of claim 1 , wherein the gradient is determined by the equation (3*Slope 1−4*Slope2+Slope3)/2.
3. The method of claim 1 , further comprising:
detecting the timing-based-servo marks on the tape cartridge; and
assembling, electronically, the timing-based-servo marks into the one or more M-patterns.
4. The method of claim 1 , wherein the timing-based-servo marks are written at a 45-degree angle relative to a servo track of a magnetic media.
5. The method of claim 1 , wherein the tape cartridge is a single-reel tape cartridge that stores a tape-media, and wherein the tape-creep is determined for the tape-media stored in the single-reel tape cartridge.
6. The method of claim 1 , wherein the tape cartridge is a dual-reel tape cassette that stores a tape-media, and wherein the tape-creep is determined for the tape-media stored in the dual-reel tape cassette.
7. The method of claim 1 , further comprising:
recording data in the tape cartridge in a parallel-serpentine pattern.
8. The method of claim 1 , further comprising:
recording data in the tape cartridge in a helical-scan pattern.
9. The method of claim 1 , wherein determining whether the gradient is demonstrative of tape-creep comprises:
comparing, during a write operation, the gradient against a threshold;
identifying that the threshold has been exceeded; and
terminating the write operation before existing data can be overwritten.
10. The method of claim 9 , further comprising:
alerting a user, with an indication, that the threshold has been exceeded.
11. A system comprising:
a tape drive; and
a tape cartridge with timing-based-servo marks, wherein the tape drive writes to the tape cartridge, and wherein the tape drive is configured to perform the operations comprising:
calculating slopes for three successive timing-based-servo marks in a timing-based-servo group, wherein the timing-based-servo marks are arranged in one or more M-patterns, and wherein the three successive timing-based-servo marks are across the one or more M-patterns;
performing a parabolic fit of a gradient of the slopes; and
determining whether the gradient is demonstrative of tape-creep.
12. The system of claim 11 , wherein the gradient is determined by the equation (3*Slope 1−4*Slope2+Slope3)/2.
13. The system of claim 11 , wherein the operations further comprise:
detecting the timing-based-servo marks on the tape cartridge; and
assembling, electronically, the timing-based-servo marks into the one or more M-patterns.
14. The system of claim 11 , wherein the timing-based-servo marks are written at a 45-degree angle relative to a servo track of a magnetic media.
15. The system of claim 11 , wherein the tape cartridge is a single-reel tape cartridge that stores a tape-media, and wherein the tape-creep is determined for the tape-media stored in the single-reel tape cartridge.
16. The system of claim 11 , wherein the tape cartridge is a dual-reel tape cassette that stores a tape-media, and wherein the tape-creep is determined for the tape-media stored in the dual-reel tape cassette.
17. The system of claim 11 , wherein the operations further comprise:
recording data in the tape cartridge in a parallel-serpentine pattern.
18. The system of claim 11 , wherein the operations further comprise:
recording data in the tape cartridge in a helical-scan pattern.
19. The system of claim 11 , wherein determining whether the slope is demonstrative of tape-creep comprises:
comparing, during a write operation, the slope against a threshold;
identifying that the threshold has been exceeded; and
terminating the write operation before existing data can be overwritten.
20. The system of claim 19 , wherein the operations further comprise:
alerting a user, with an indication, that the threshold has been exceeded.