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Generic restore from LTO tapes

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Neil Sadwelkar
Generic restore from LTO tapes
on Jun 9, 2017 at 7:58:31 am

Many people have old LTO-3, 4, 5 tapes with contents which are archives from finishing systems. Like Quantel Editbox, Quantel eQ, iQ, Pablo, Autodesk Smoke, Fire, Flame. And since the host application that wrote them is deprecated and unavailable, is there a way or a software that can simply read these tapes and offload the contents to a hard drive?

So that one can take the drive to the newer version of the finishing software and read the archive and extract media? Provided that today's version of the software can actually do something with an archive made in the older version.

My question is not how to 'open' the files on the LTO tape. That part I'll have to do on a case by case basis. I just need to know how to read it off the LTO and write it to a hard disk file for file. Or is that even possible without knowing how the content was written.

Similarly, I know of LTO tapes written in the 2004-2008 period using something called (AFAIR) Windows Backup which was probably part of Windows NT or something. Can these be restored in some way?

-----------------------------------
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India


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Tim Jones
Re: Generic restore from LTO tapes
on Jun 9, 2017 at 10:46:18 am

Hi Neil,

That's what the TOLIS Tape Tools parts which are included with your BRU PE license are for - the "taperead" tool specifically in this case. It will allow you to read raw data from any tape and output that data to a disk file (or pipe it into another tool like tar or cpio). The downside is that you do need to have a basic understanding of how the tape was originally written including the block size that was used when writing the tape since there is no mechanism to ask a tape how it was written - variable vs. fixed block, 512b, 1024b, or another block size, etc. - to be able to properly read the content. You then need to understand how the originating software containerized the data when writing it to the tape (e.g.: tar, cpio, pax, bru, mtf, etc.) so that you can do something with the raw information once it is read from the tape.

For instance, to read a tape created with a Cache-A unit in tar format, we know two things - the tape was written in ustar format and it was written with a -b 300 blocking factor (tar uses 512-byte blocks, so that's 150KB). To read a segment from that tape, you would use a command like this:

taperead -b 150k -f ntape0 | tar -tvvf - -b 300

That reads the raw data on the tape and sends it out via taperead's "stdout" channel and then pipes it into tar's "stdin" channel and would show you a table of contents (file listing) for the current segment on the tape.

For other formats, you would use a similar syntax, adjusting the -b argument as required, and sending the output to a disk file using redirection (">") or to an app like tar using a pipe ("|").

Tim
--
Tim Jones
CTO - TOLIS Group, Inc.
http://www.tolisgroup.com
BRU ... because it's the RESTORE that matters!


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Neil Sadwelkar
Re: Generic restore from LTO tapes
on Jun 9, 2017 at 2:02:20 pm

Tim,

Thanks. I am finding out first which host application wrote these tapes. It would vary between Quantel eQ/iQ systems, Autodesk Smoke/Flame systems. I've written to support at these companies to find out the info you mentioned - block size, container, format any other info they may have. Then, of course, testing.

Many companies have a large collection of LTO-2, LTO-3, LTO-4 tape with these mixed contents. I am urging them to discover what's in them and to migrate the tapes to LTO-7 for future archive. This would also save them space with one LTO-7 taking care of 20-25 LTO-2 tapes, or 12-15 LTO-3 tapes.

Of course, the oldest LTO drive I have is an LTO-5, so if the quantity of LTO-2 is large, I'll need to go buy an LTO-4 or LTO-3 drive.

-----------------------------------
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India


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Tim Jones
Re: Generic restore from LTO tapes
on Jun 9, 2017 at 3:56:14 pm

The good news is that Autodesk uses tar for those system tapes. The big question there is simply the block size value.

One point of note - if you run into Quantum LTO-A tapes (the pre-cursor to Cache-A), those are a custom format and unless someone from Quantum's old Seagate team can shed light on the container format, those are gone forever unless you can locate an LTO-3A or LTO-4A drive in the wild.

Tim
--
Tim Jones
CTO - TOLIS Group, Inc.
http://www.tolisgroup.com
BRU ... because it's the RESTORE that matters!


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