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Unecoverable Cache-A Tape
Posted by Mike Drew on July 24, 2013 at 4:45 amHi all, does anyone have any suggestions on how to recover data from a Cache_A LTO5 tape? We have one tape that is the first of a 3 tape set that will not restore any data. Cache-A have tried but with no luck. I now have serious doubts about the reliability of this system. I have been with this company only a few months and they tell me similar stories going back a few years since they bought the system. Any suggestions would be much appreciated.
Mike
Mike Drew
Operations ManagerTim Jones replied 12 years, 9 months ago 3 Members · 8 Replies -
8 Replies
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Tim Jones
July 24, 2013 at 3:15 pmHi Mike,
Was this a TAR tape or an LTFS tape? I may have some ideas that have worked for others in this situation.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.productionbackup.com
BRU … because it’s the RESTORE that matters! -
Tim Jones
July 24, 2013 at 9:05 pmIf you have a non-Cache-A LTO-5 drive, our TOLIS Tape Tools will let you restore the tape onto a Mac system. To see if we can get there for you (i.e. the tape truly isn’t blown away), try downloading and installing our BRU PE demo and then execute the following command from the Terminal:
tapectl rewind
tapectl tell
tapectl seod
tapectl tell
The first number returned should be 0 and the second number should be a much larger value depending on how much data should be on the tape. If the 2 numbers are 0 and 4 (or something close like that), it means that the tape is truly taking a dirt nap and here’s no way to get the data off of it. However, if the numbers are much more separated (i.e. 0 and 2,000,000±), the data’s there and we will probably be able to get it back for you.Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.productionbackup.com
BRU … because it’s the RESTORE that matters! -
Mike Drew
July 24, 2013 at 9:49 pmThanks Tim, no we don’t have a stand alone LTO5 drive. I will try and borrow one. Any Other thoughts?
Mike
Mike Drew
Operations Manager -
Tim Jones
July 24, 2013 at 10:19 pmLots of thoughts, but they all are dependent on having that standalone drive… You can only use teh Cache-A drive under the Cache-A methodology.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.productionbackup.com
BRU … because it’s the RESTORE that matters! -
Tom Goldberg
August 5, 2013 at 11:11 pmMike,
Because we have looked at this tape, we know that the EOD (End Of Data) maker is at the beginning of the tape. As I explained to you, the only way we know of that this can happen is if the tape is erased.
We are advised by our OEM partners HP, that the standards of the LTO consortium do not allow anyone to read data past the EOD marker. This is why we would have to send the tape to HP as a consortium member for recovery and have offered to do so. That offer still stands.
Tom Goldberg
Cache-A Corporation
433 Park Point Drive #285
Golden, CO 80401
mailto:tom.goldberg@cache-a.com
https://cache-a.com -
Mike Drew
August 5, 2013 at 11:58 pmHi Tom, thank you for the offer. I would like to apologize for my ranting as I was under pressure and upset that this has happened. I will take you up on the offer. I will now take this off list.
Many thanks
Mike Drew
Mike Drew
Operations Manager -
Tim Jones
August 5, 2013 at 11:58 pmTom is very correct in this – the only way that EOD can be at the beginning of the tape is if it was erased or if you started to overwrite the tape and then aborted the operation immediately after the tape was opened for write.
To recover data from this situation requires a special drive that is capable of ignoring the EOD marker on a tape and that is only available at HP’s facility.
Tim
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Tim Jones
CTO – TOLIS Group, Inc.
https://www.productionbackup.com
BRU … because it’s the RESTORE that matters!
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