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Multiple Questions Regarding Rebuild Situations


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#1 SethR

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Posted 22 May 2017 - 08:10 PM

For reference, I am using Retrospect 13.0.1 on OSX 10.10.5. 

 

I am going through and working on the rebuild/restoration of a large assortment of tapes that were created eight years ago and in trying to piece together what was done eight years ago, I've come into some questions about the workings of Retrospect and understanding how it works with media sets and rebuilds.

 

Currently, I have a multitude of tape sets that have had their catalog files lost to the sands of time and with multiple sets, tapes are either missing or damage. Thus, I'm curious how Retrospect works with the following scenarios:

 

1 - There is a tape set with 4 tapes. Tapes 1 & 2 are fine. Tapes 3 & 4 are damaged. There is no catalog file present. Can I rebuild the media set for tapes 1 & 2 and just leave tapes 3 & 4 off? Or can I rebuild what it can from 3 & 4 as well? Basically - during a rebuild is it all or nothing on a tape?

 

2 - There is a tape set of 15 tapes. Tape 6 is damaged. Catalog file is missing. Can I rebuild the media set for 1-5, skip 6, and then move to 7-15?

 

3 - There is a tape set of 5 tapes. Tapes 1, 2, and 3 are missing/unable to be read. Catalog file is missing. Can I rebuild the media set for just 4 & 5?

 

4 - Can data just be dumped from a tape onto a drive? If I have a damaged tape with no catalog file for it, rebuilds are partial but fail. Can I just have it dump the data out that it can read?

 

Thanks!



#2 twickland

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Posted 22 May 2017 - 09:21 PM

1 - There is a tape set with 4 tapes. Tapes 1 & 2 are fine. Tapes 3 & 4 are damaged. There is no catalog file present. Can I rebuild the media set for tapes 1 & 2 and just leave tapes 3 & 4 off? Or can I rebuild what it can from 3 & 4 as well? Basically - during a rebuild is it all or nothing on a tape?

You should be able to rebuild the catalog for everything that's readable. When Retrospect encounters trouble reading a tape, it will ask if you want to save the partial rebuild; you should say yes. Then, select the same media set, but instead of clicking on "rebuild," click "repair," and insert the next available tape member. Continue until no more tape members are available.

 

2 - There is a tape set of 15 tapes. Tape 6 is damaged. Catalog file is missing. Can I rebuild the media set for 1-5, skip 6, and then move to 7-15?

Without a catalog, Retrospect has no way of knowing in advance how many members there are in the media set, and will just ask for them sequentially. When it asks for member tape 6 during the rebuild, simply click "missing" and insert tape 7.  Or, you could try to read whatever data you can from tape 6, and then follow the steps I outlined above.

 

3 - There is a tape set of 5 tapes. Tapes 1, 2, and 3 are missing/unable to be read. Catalog file is missing. Can I rebuild the media set for just 4 & 5?

Yes. You will just need to click "missing" when Retrospect asks for members 1, 2, and 3.

 

4 - Can data just be dumped from a tape onto a drive? If I have a damaged tape with no catalog file for it, rebuilds are partial but fail. Can I just have it dump the data out that it can read?

AFIK, no.


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#3 Lennart Thelander

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Posted 23 May 2017 - 05:30 AM

In addition to Twickland's excellent answers, I would like to add this:

 

Try a cleaning tape, if you have not done so. That can help you read the tapes.

 

If the tape station has been in daily use for eight years, it might be worn out and need replacement or at least servicing.






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