[clug] Can I re-record just the first record of a tape?

[Antti.Roppola at brs.gov.au]

I used to put multiple archives onto single Exabyte tapes
as described. I never went and tried to update previous archives
though, I am guessing it would work as long as you didn't
write beyond the end of your first archive (naturally).

The mt manpage says that fsf forwards over EOF marks, which suggests
that if you fsf'ed to the second EOF, that'd be the start of your data.

Easy enough to test.

Antti


-----Original Message-----
From: Martin Pool [mailto:mbp at samba.org]
Sent: Monday, 28 July 2003 3:18 PM
To: Michael.James at csiro.au
Cc: linux at lists.samba.org
Subject: Re: [clug] Can I re-record just the first record of a tape?


On 28 Jul 2003, Michael.James at csiro.au wrote:

> Can I reliably come back and re-record the logfile after,
>  without messing up the inter-record gap
>  and zapping the following records?

When I used QIC tapes years ago you couldn't do this.  A lot of tape
software seems to be built on the assumption that you can only write
tapes straight through, so I suppose it may be true.

But some tapes can seek (mt seek/tell), so perhaps if your hardware
does that, you can leave 'enough' space for the index, and then skip
over it to write the data.



Just because I like the way you write technical questions in blank
verse:

In the beginning was the Tao.
  The Tao gave birth to Space and Time.
  Therefore, Space and Time
  are the Yin and Yang of programming.

Programmers that do not comprehend the Tao
  are always running out of time and space
  for their programs.
Programmers that comprehend the Tao
  always have enough time and space
  to accomplish their goals.

How could it be otherwise? 

-- 
Martin