formatting DAT tapes

[HSW Support]

What is the best/quickest way of ensuring sensitive information is removed from DDS tapes prior to re-use.

Thanks in advance,

Mike

[Vincenzo Restuccia]

mediainit /dev/rmt/0m

[Andreas Voss · Accepted solution]

Hi,

here an endless loop:

prealloc /var/tmp/scratch 1048576
while :
do
cat /var/tmp/scratch
done | dd of=/dev/rmt/0m bs=10k

This loop writes until end of tape and then gives an I/O error.
After that remove the scatch file.

Regards

[Volker Borowski]

Hi,

if you like to know what is written to the tape (mediainit is somewhat hidden, and the man page does not say what and how much is written), you can also use

telnet localhost chargen | dd of=/dev/rmt/0m bs=1k

with this you can also verify, how many blocks are transferred to the tape, to see if it has been written to the very end.

Volker

[Thierry Poels_1]

okay one more,

1. Determine if the /dev/zero pseudo driver is available:

# lssf /dev/zero
pseudo driver mm minor 0x000003 /dev/zero

Note: If /dev/zero is not available, then execute the following command to create the driver:

# mknod /dev/zero c 3 0x00003

2. Overwrite all of the data with zeros:

# dd if=/dev/zero of=/dev/rmt/0m

good luck,
Thiery.
(I have some other ideas but they are not compatible with the word 'reuse' ;-)

[paul courry]

Gentlemen, I'm in favor of an old fashioned demagnitizer from Radio Shack. It's fast, it's cheap, it provides a reasonable level of protection from somebody who wants to read the tape. You can then do a media init to make the tape usable. Of course if you *really* want to make sure the data is gone you need to burn the tape (gasoline makes a wonderful fire) or do a number of passes over it with a random pattern of data.

How much effort you put out demands on who you are protecting the data from. Are you protecting atomic secrets from foreign governments? Or are you protecting the company financials from your competitor down the street?