Old 8mm tape extraction issues

Hello,

I'm having a problem extracting an old 8mm tape. The tape was written
with tar, but the creator created a tar on the first block, then
started another tar at the next block, and so on. A wrench is added
to the mix, since they somehow wrote some of the tars to be spanned
from one block to another (WOW!!!!!). So, I have the following
questions ------>

1. Is there an easy way (ie. without perl) to just pull every occupied
block on the tape as individual files, then just untar the extracted
files on disk? The problem is: I don't know how many tar files were
started on new blocks, so I just want to pull the whole darn thing,
and deal with the individual files from there, rather than guessing at
which blocks will have data, and which will not.


2. When some of the blocks are untarred, a prompt comes up at the end
requesting, "Place next tape in drive, and press enter:" - indicating
that the particular tar file was somehow spanned onto another
block(?). How can I force tar to point to the appropriate tar file,
for the rest of the spanned tar? The problem is: When I extract
these particular lovelies, I get partial files, where the rest of the
file was placed on the next tar. I need to put these files back
together, somehow.

Any info would be great!

Thanks -

Peter

Re: Old 8mm tape extraction issues

On Wed, 10 Oct 2007 22:56:13 -0000, gibbonsp
wrote:

>Hello,
>
>I'm having a problem extracting an old 8mm tape. The tape was written
>with tar, but the creator created a tar on the first block, then
>started another tar at the next block, and so on. A wrench is added
>to the mix, since they somehow wrote some of the tars to be spanned
>from one block to another (WOW!!!!!). So, I have the following
>questions ------>
>
>1. Is there an easy way (ie. without perl) to just pull every occupied
>block on the tape as individual files, then just untar the extracted
>files on disk? The problem is: I don't know how many tar files were
>started on new blocks, so I just want to pull the whole darn thing,
>and deal with the individual files from there, rather than guessing at
>which blocks will have data, and which will not.
>
>
>2. When some of the blocks are untarred, a prompt comes up at the end
>requesting, "Place next tape in drive, and press enter:" - indicating
>that the particular tar file was somehow spanned onto another
>block(?). How can I force tar to point to the appropriate tar file,
>for the rest of the spanned tar? The problem is: When I extract
>these particular lovelies, I get partial files, where the rest of the
>file was placed on the next tar. I need to put these files back
>together, somehow.
>
>Any info would be great!
>
>Thanks -
>
>Peter

What OS are you using? Sounds to me like you want to extract the files
using the "no rewind" tape device (eg. /dev/nst0 on my Slackware
boxen, or /dev/nurStp0 on SCO OpenServer) and keep running consecutive
tars until end of tape or data.


Scott McMillan

Re: Old 8mm tape extraction issues

On 2007-10-11, Scott McMillan wrote:
> On Wed, 10 Oct 2007 22:56:13 -0000, gibbonsp
> wrote:
>
>>Hello,
>>
>>I'm having a problem extracting an old 8mm tape. The tape was written
>>with tar, but the creator created a tar on the first block, then
>>started another tar at the next block, and so on. A wrench is added
>>to the mix, since they somehow wrote some of the tars to be spanned
>>from one block to another (WOW!!!!!).

And?

[snippage]

> What OS are you using? Sounds to me like you want to extract the files
> using the "no rewind" tape device (eg. /dev/nst0 on my Slackware
> boxen, or /dev/nurStp0 on SCO OpenServer) and keep running consecutive
> tars until end of tape or data.

That and judicious use of the 'mt fsf' command should make retrieving this stuff
a doddle. My personal backup tapes consist of a tar file followed by a ufsdump
on the same tape - use of the mt command and non-rewinding device make this easy
to do.


--
"Religion poisons everything."
[email me at huge {at} huge (dot) org uk]