Splitting tar output, Resolved

[Jim Kuzdrall]

> You did, but it's no big deal.  If you're going to do
> mea culpas about your email format I'd rather it was about
> your MIME headers forcing a UTF-8 charset on us...            ;->

    Switched to iso-8859-1.  Is that better?

    Your suggest and that of maddog were both on target.  However, your 
last was the best - take a few deep breaths...

    I am in the midst of installing or upgrading 4 different computers 
(all different hardware, including 2 Dell laptops) to SuSE 9.3.  They 
were running RH 7.3 or SuSE 8.2, so you can see that I haven't been 
into the gears and levers for a while.  The SuSE "upgrade" wiped out 
uncounted preferences and setups.  I am guessing that is where the 
UTF-8 came from.
>
> What do we know about this tape drive?  Has it ever been seen to
> work?  Under what circumstances?  ...
>
    The problems with the tape reading commenced with the upgrade.  I 
have been making the tapes for off-site storage.  The disk file is more 
handy than the bank's Safe Deposit box.  I completely restored the 
primary system several times from tape 2 years ago after a massive 
motherboard failure, so it used to work.  I just forgot how to set the 
blocking factor when I was testing the tee outputs.  i.e. size/512 not 
size for tar.

    There is lots to learn and remember, especially if you don't work 
with the details regularly.  I usually try to bury everything in 
scripts rather than remember.
>
> Writing the disk file first and then cloning it to tape is
> almost certainly the most efficient approach, and likely the
> most reliable, as well...

    That is essentially what I have been doing.  It takes over 1.5 hours 
to write the tape and only 15min for tar to produce the 11GB file.  
Since the time to transfer data via SCSI to the tape is negligible, tar 
can keep up with the tape, completing both tasks in 1.5 hour.

    It is a small gain, but I was eager to optimize.  And to increase my 
understanding of Linux - which is progressing ever so slowly.

    The script I will try is:
cd /
(tar -cf - ./ $bkoptions) | (tee $bkdir/monthly.tar | dd of=/dev/st0 
ibs=512 obs=4096)

    I am presently timing the operation versus output block size.  It 
probably needs to be increased to 16K if the drive accepts it.  The 
tape drive uses up the 4K every 2ms at 2MB/s writing speed.

    I will post the final results.

> Heh.  Now sounds like a good time to stop and take a few deep
> breaths, and maybe even make a few therapeutic BAC adjustments,..

    When it stops raining, it will be a day at the beach.  For now I 
will content myself with a dish of ice cream and a nap.

    Thank you and everybody else on this great gnhlug resource.

Jim Kuzdrall