Surestore Ultrium 230 - no sufficient margin

[Greg Talmo]

This is in regards to a used C7401A I recently acquired and have been running L&TT against.

Running the L&TT "LTO Drive Assessment Test" fails saying that the drive/media fails with a "could not write to the data cartridge with sufficient margin". I've tried several different cartridges (and brands), with the same results.

I have updated to the most recent firmware (via L&TT and the web) to no avail.

Based on the test, L&TT suggests the drive shouldn't be used.

Thus, 2 questions:
1) what does "margin" mean, or refer to, in this case?
2) Is there hope for this drive?

Thanks!

(I've attached the test resultlog from L&TT)

- G

[thomas rush]

The tape geeks use margin to refer to the margin of error, essentially. When a tape is written, we can read it back if the signals are strong enough, and the number of errors is low enough (the signals written are much stronger than they need to be, and there is lots of redundant data written to be able to recover from even a large number of errors). In this case, it means that the signals are weaker or there are more errors than considered safe. If you get enough errors, you won't be able to read the tape back reliably, and it sounds like you're out of that safe range.

You could consider upgrading to LTO-2 or even LTO-3 tape drive, both of which will read your older LTO-1 tapes. The LTO-2 drive will even be able to write to the older tapes. LTO-2 is twice the capacity, LTO-3 four times the capacity of your current tapes (and significantly faster, as well, if your disks are fast enough.

[Rajanikant · Accepted solution]

hi Greg,

I have not seen this before. In the L&TT, you will be able to create a Support ticket, if you can create and attatch it to this I will be able to tell you the exact status of the drive

Regards

Raj

[Greg Talmo]

Raj,
Thanks for looking into this!

The LT&T Support Ticket is attached -- I think this is the right one, if not let me know and I'll run another.

Thanks again!

- G

[meloni]

Greg, I reviewed the ticket you attached, and probably your drive is ok.
There are indication that the tapes you are using where previously used in another drive, and it report strange value.
The calculation on the margin you saw during the assesment test indicate a problem during write process, but as there is no way to identify if the problem is on the tape or on the head of the drive, I would suggest you to run a few cleaning cycle and to run a new test with a brand new tape, so you will have clear if the problem is on the tapes or on the drive.
Also the HBA you are using for this test is limiting the throughput of the data, but this is not causing the margin error