Problem reading from tape drive -- SOLVED, or at least a workaround

Renee Gehlbach fbsd-ml at
Thu Sep 1 16:28:22 UTC 2011

>> Is there any way I could test to make sure this is in fact what's happening?
> Try writing several files to the tape,  each in it's own operation,
> and issue a 'mt -bsf' between each operation.
> THEN try reading from the tape.  with just successive 'read' operations.
>    *NO* 'mt' positioning
> If everything is working 'properly', there will be *ONLY*ONE* file on the tape.
> If there is an O/S failure to 'backspace on close' you'll get all the original
> files, one on each read attempt.
> If the O/S has a _complete_ 'failure to backspace', you'll get a tape that
> functions identially to your earlier tests -- you can find all the file
> by 'mt -fsf' between reads
> Other things to try.
>    1) *write* a multi-file tape under Unbuntu, and try to read it under FreeBSD.
>    2) *write* a multi-file tape under FreeBSD, and try to read it under Unbuntu.
>    3) If there are read issues, see if  the 'mt -fsf' hack allows you to
>       find everything.
OK, it's definitely an O/S failure to backspace on close, because the 
tape does read properly when I manually backspace after each file.
>>                        Unfortunately, the "workaround" of running mt -fsf
>> after every file read
> if it worked, 'mf -bsf' after every _write_ would be a better solution.<grin>
> But it probably suffers from the same 'not really usable' defect.
*cheers* And YES!!!! That's a usable workaround!  Luckily enough, Bacula 
will run a script after each backup job, all I'll have to do is add a mt 
-bsf command to that script!

> _I_ have no clue what 'bacula' is -- sounds sort-of like a Transylvanian
> back-up utility.  One with 'fangs' init, and issues with mirrors.<grin>
Close!  It's a multi-platform client-server backup application.  Its 
tagline used to be something like "Comes in the night, and sucks the 
essence from your computers."  When I went to check the precise wording, 
though, it's no longer on their logo.  I guess someone objected.....too 
bad, I got a kick from that tagline.  I find it to be a great 
open-source replacement for backup exec.  I can have the Bacula server 
and tape drive on one FreeBSD or Linux box, and install clients on all 
of my other FreeBSD & Linux servers, and Linux & Windows desktops to 
back them all up to that one tape drive.

Thanks for all of your help!!!!!!

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