LTO5 Read Warning (insufficient margin)

[bergerb]

Hello,

just got my used LTO5-Drive. Bit of a pain to setup, but now everything seems to be running and I can write data to the tape.

The Drive-Assesment-Test succeeded with great margins.

After writing some data, I found the following Warning in the Health-Check:

Drive Health>Drive>Read (last 1 tape) :
Previous tape (... LTO-5) load count 3469 : Warning (insufficient margin) (12.1 GB)

Is this something to be concerned about? What does that warning want to tell me?

Thanks
bergerb

[Curtis_Ballard · Accepted solution]

Tape drives report capacity values that are lower than what can actually fit onto a tape when everything is in perfect condition.  As everything wears the amount of data that can be written will slowly decline.  The tapes and the tape drive will wear at different rates depending on use.  When LTT detects that a read or write had more capacity loss than is considered normal then it will generate the 'insufficient margin' warning.

The values reported on a read are due to the last time that the tape was written and report information that is most applicable to the drive that wrote the tape.  In some cases it can be multiple drives appending to different parts of the tape.

[bergerb]

Ah, okay, thanks for the explanation!

Alright, after some writing and reading, and also informing myself, I am now more unclear on what to do, than before

During my Read-Write Journey, I encountered the following error:

Rule 15.4 (Capacity Loss/Offtrack):
This drive has shown signs of going off track during writing with cartridge s/n.
Please try another cartridge. If the problem reoccurs with another cartridge, then please contact support.

Also a lot of capacity loss:

Spoiler

wrap 0 partially written
wrap 4 7.08%
wrap 5 2.40%
wrap 6 18.60%
wrap 7 2.65%
wrap 8 10.90%
wrap 9 2.58%
wrap 10 20.19%
wrap 11 1.87%
wrap 12 2.73%
wrap 13 0.65%
wrap 14 3.87%
wrap 15 0.72%
wrap 16 1.86%
wrap 17 1.21%
wrap 18 19.05%
wrap 19 1.58%
wrap 20 24.04%
wrap 21 1.06%
wrap 22 2.55%
wrap 23 90.18%

Write-Faults (Table-Feature doesn't like me):

Spoiler

+-------------+------------------+----------------+--------------+------------------+
| Wrap number | Wrap write count | Offtrack count | Servo faults | Dataset rewrites |
+-------------+------------------+----------------+--------------+------------------+
|           0 |                0 |              0 |            0 |                0 |
|           1 |                0 |              0 |            0 |                0 |
|           2 |                0 |              0 |            0 |                0 |
|           3 |                0 |              0 |            0 |                0 |
|           4 |                1 |            531 |            0 |                0 |
|           5 |                1 |           1840 |            0 |                0 |
|           6 |                1 |           7555 |            0 |                0 |
|           7 |                1 |           2277 |            0 |                0 |
|           8 |                1 |           5012 |            0 |                0 |
|           9 |                1 |           2042 |            0 |                0 |
|          10 |                1 |           5997 |            0 |                0 |
|          11 |                1 |           1642 |            0 |                0 |
|          12 |                1 |            709 |            0 |                1 |
|          13 |                1 |            633 |            0 |                0 |
|          14 |                1 |            348 |            0 |                1 |
|          15 |                1 |            623 |            0 |                0 |
|          16 |                1 |            309 |            0 |                0 |
|          17 |                1 |            784 |            0 |                0 |
|          18 |                1 |           4006 |            0 |                0 |
|          19 |                1 |            844 |            0 |                0 |
|          20 |                1 |           3360 |            0 |                1 |
|          21 |                1 |            822 |            0 |                0 |
|          22 |                1 |              4 |            0 |                0 |
|          23 |                1 |              0 |            0 |                0 |
|          24 |                0 |              0 |            0 |                0 |
|          25 |                0 |              0 |            0 |                0 |
|          26 |                0 |              0 |            0 |                0 |
|          27 |                0 |              0 |            0 |                0 |
+-------------+------------------+----------------+--------------+------------------+

Interestingly, now everything is ok, no OffTrack-Errors and much less capacity loss

Spoiler

wrap 0 partially written
wrap 4 13.55%
wrap 5 1.19%
wrap 6 1.01%
wrap 7 0.68%
wrap 8 1.05%
wrap 9 0.35%
wrap 10 1.94%
wrap 11 0.78%
wrap 12 1.47%
wrap 13 0.27%
wrap 14 2.36%
wrap 15 0.22%
wrap 16 2.33%
wrap 17 0.28%
wrap 18 1.67%
wrap 19 0.28%
wrap 20 2.04%
wrap 21 0.64%
wrap 22 1.83%
wrap 23 0.95%
wrap 24 0.65%
wrap 25 0.56%
wrap 26 0.78%
wrap 27 0.60%
wrap 28 1.00%
wrap 29 0.38%
wrap 30 0.63%
wrap 31 1.09%
wrap 32 1.83%
wrap 33 1.37%
wrap 34 1.13%
wrap 35 1.03%
wrap 36 0.96%
wrap 37 0.74%
wrap 38 1.26%
wrap 39 1.27%
wrap 40 1.86%
wrap 41 0.62%
wrap 42 1.22%
wrap 43 0.44%
wrap 44 1.59%
wrap 45 0.46%
wrap 46 1.06%
wrap 47 0.64%
wrap 48 1.91%
wrap 49 0.54%
wrap 50 1.06%
wrap 51 0.65%
wrap 52 2.06%
wrap 53 0.63%
wrap 54 1.24%
wrap 55 0.62%
wrap 56 1.13%
wrap 57 0.55%
wrap 58 1.49%
wrap 59 0.51%
wrap 60 partially written

Some Ideas on what happened? Did the head clean itself with my tape?

My first attempts were via Windows-Copy, could that result in an OffTrack Error?

Formatting is horrible with that editor.. keeps telling me that HTML is incorrect..

[bergerb]

Okay, happy too soon.

Write Faults:

Spoiler

+-------------+------------------+----------------+--------------+------------------+
| Wrap number | Wrap write count | Offtrack count | Servo faults | Dataset rewrites |
+-------------+------------------+----------------+--------------+------------------+
|           0 |                1 |              0 |            0 |                0 |
|           1 |                0 |              0 |            0 |                0 |
|           2 |                0 |              0 |            0 |                0 |
|           3 |                0 |              0 |            0 |                0 |
|           4 |                2 |            768 |            0 |                0 |
|           5 |                1 |            707 |            0 |                0 |
|           6 |                1 |            546 |            0 |                0 |
|           7 |                1 |            627 |            0 |                0 |
|           8 |                1 |            659 |            0 |                0 |
|           9 |                1 |            539 |            0 |                0 |
|          10 |                1 |            707 |            0 |                0 |
|          11 |                1 |            494 |            0 |                0 |
|          12 |                1 |            788 |            0 |                0 |
|          13 |                1 |            540 |            0 |                0 |
|          14 |                1 |            803 |            0 |                0 |
|          15 |                1 |            530 |            0 |                0 |
|          16 |                1 |            709 |            0 |                0 |
|          17 |                1 |            516 |            0 |                0 |
|          18 |                1 |            705 |            0 |                0 |
|          19 |                1 |            537 |            0 |                0 |
|          20 |                1 |            767 |            0 |                0 |
|          21 |                1 |            727 |            0 |                0 |
|          22 |                1 |            689 |            0 |                0 |
|          23 |                1 |            742 |            0 |                0 |
|          24 |                1 |            679 |            0 |                0 |
|          25 |                1 |            679 |            0 |                0 |
|          26 |                1 |            603 |            0 |                0 |
|          27 |                1 |            541 |            0 |                0 |
|          28 |                1 |            824 |            0 |                0 |
|          29 |                1 |            662 |            0 |                0 |
|          30 |                1 |            488 |            0 |                0 |
|          31 |                1 |            763 |            0 |                0 |
|          32 |                1 |            683 |            0 |                0 |
|          33 |                1 |            638 |            0 |                0 |
|          34 |                1 |            532 |            0 |                0 |
|          35 |                1 |            655 |            0 |                0 |
|          36 |                1 |            701 |            0 |                0 |
|          37 |                1 |            775 |            0 |                0 |
|          38 |                1 |            425 |            0 |                0 |
|          39 |                1 |            724 |            0 |                0 |
|          40 |                1 |            612 |            0 |                0 |
|          41 |                1 |            377 |            0 |                0 |
|          42 |                1 |            756 |            0 |                0 |
|          43 |                1 |            382 |            0 |                0 |
|          44 |                1 |            517 |            0 |                0 |
|          45 |                1 |            465 |            0 |                0 |
|          46 |                1 |            856 |            0 |                0 |
|          47 |                1 |            359 |            0 |                0 |
|          48 |                1 |            634 |            0 |                0 |
|          49 |                1 |            561 |            0 |                0 |
|          50 |                1 |            819 |            0 |                0 |
|          51 |                1 |            464 |            0 |                0 |
|          52 |                1 |            676 |            0 |                0 |
|          53 |                1 |            418 |            0 |                0 |
|          54 |                1 |            606 |            0 |                0 |
|          55 |                1 |            422 |            0 |                0 |
|          56 |                1 |            368 |            0 |                0 |
|          57 |                1 |            463 |            0 |                0 |
|          58 |                1 |            494 |            0 |                0 |
|          59 |                1 |            369 |            0 |                0 |
|          60 |                1 |           1680 |            0 |                0 |
|          61 |                2 |           2161 |            0 |                0 |
|          62 |                2 |            632 |            0 |                0 |
|          63 |                1 |           1128 |            0 |                0 |
|          64 |                1 |            568 |            0 |                0 |
|          65 |                1 |            798 |            0 |                0 |
|          66 |                1 |            655 |            0 |                0 |
|          67 |                1 |            831 |            0 |                0 |
|          68 |                1 |            610 |            0 |                0 |
|          69 |                1 |            821 |            0 |                0 |
|          70 |                1 |            660 |            0 |                0 |
|          71 |                1 |            722 |            0 |                0 |
|          72 |                1 |            886 |            0 |                0 |
|          73 |                1 |            623 |            0 |                0 |
|          74 |                1 |            592 |            0 |                0 |
|          75 |                1 |            799 |            0 |                0 |
|          76 |                1 |            696 |            0 |                0 |
|          77 |                1 |            759 |            0 |                0 |
|          78 |                1 |            796 |            0 |                0 |
|          79 |                1 |            989 |            0 |                0 |
+-------------+------------------+----------------+--------------+------------------+

Capacity Loss:

Spoiler

wrap 0 partially written
wrap 4 4.49%
wrap 5 0.91%
wrap 6 4.14%
wrap 7 0.79%
wrap 8 5.36%
wrap 9 0.78%
wrap 10 4.97%
wrap 11 0.74%
wrap 12 4.55%
wrap 13 0.76%
wrap 14 6.79%
wrap 15 0.67%
wrap 16 4.90%
wrap 17 0.74%
wrap 18 6.86%
wrap 19 0.82%
wrap 20 5.44%
wrap 21 0.94%
wrap 22 13.63%
wrap 23 0.92%
wrap 24 9.72%
wrap 25 0.88%
wrap 26 14.60%
wrap 27 0.74%
wrap 28 14.49%
wrap 29 0.86%
wrap 30 7.96%
wrap 31 0.95%
wrap 32 13.45%
wrap 33 0.87%
wrap 34 12.03%
wrap 35 0.87%
wrap 36 11.05%
wrap 37 0.96%
wrap 38 12.32%
wrap 39 0.92%
wrap 40 9.94%
wrap 41 0.55%
wrap 42 8.99%
wrap 43 0.60%
wrap 44 14.36%
wrap 45 0.68%
wrap 46 10.33%
wrap 47 0.55%
wrap 48 15.47%
wrap 49 0.78%
wrap 50 6.28%
wrap 51 0.69%
wrap 52 5.17%
wrap 53 0.63%
wrap 54 5.08%
wrap 55 0.60%
wrap 56 6.33%
wrap 57 0.67%
wrap 58 5.15%
wrap 59 0.53%
wrap 60 4.56%
wrap 61 1.13%
wrap 62 partially written

[Curtis_Ballard]

A few thoughts

• The tape drives do have some self cleaning with a brush that scrubs the head when the drive determines that would be a good idea so problems that are just do to some loose debris can disappear after a tape is unloaded and put back in.
• The capacity loss numbers don't look terrible - some capacity loss is normal.
• Even numbered wraps are worse than odd numbered wraps.  Those use different heads.  The heads used on those tracks might need cleaned
• Clean the drive a time or two and see how the drive performs.