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How to format tapes
- Thread starter Kems
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and i need to really format tapes (/dev/rmt/0)? I know that it is really easy, so if someone could help me?
KenCunningham
Technical User
Forget it (they don't need formatting) and have a good weekend! Cheers.
- Thread starter
- #3
KenCunningham
Technical User
No problem with The English at all. As far as erasing tapes is concerned, my advice remains 'don't bother'. Once you write something else to the tape, it becomes very difficult to read anything previously written. You could possibly use mt -f <tape_device> erase, but this takes an age and isn't, to my knowledge, 100% reliable anyway. Alternatively, a magnet should do the trick quite nicely! Good luck.
If you need to degauss the tapes for security reasons, or to just get a fresh clean tape, you can buy machines that will do it MUCH faster than trying to erase them in the drive.
This is the "magnet" approach that Ken mentioned, only you shouldn't use a magnet. Most magnets you might be able to find are too weak to actually erase the tape. Any that are strong enough to erase them will probably cause problems around any computer equipment you might have.
They make Degaussing machines just for this purpose. They usually focus and contain the field so it only erases the tape and doesn't cause other harm. Just doing a quick Google search found these...
And many others.
Hope this helps.
This is the "magnet" approach that Ken mentioned, only you shouldn't use a magnet. Most magnets you might be able to find are too weak to actually erase the tape. Any that are strong enough to erase them will probably cause problems around any computer equipment you might have.
They make Degaussing machines just for this purpose. They usually focus and contain the field so it only erases the tape and doesn't cause other harm. Just doing a quick Google search found these...
Hope this helps.
KenCunningham
Technical User
Just to clarify, my 'magnet' comment was made with tongue firmly in cheek! Sam's quite correct about the degaussing option, but it seems an expensive thing to do. Couldn't you just write rubbish to the tape until it's full?
Ken, your comment may have been tongue in cheek, but it was 100% correct. You CAN just use a strong magnet, but it's very hard to get a complete and clean degauss and you always miss spots.
I used to work for a government organization that will remain nameless. Because of security concerns, ALL tapes were required to be degaussed when a certain date had been reached, when it was to be reused, or when a tape was being decomissioned. With a degaussing machine, you can clean a tape in just several seconds without having to mount it, issue commands, and dismount it. That's several seconds verses several minutes. It's well worth it when you have a couple hundred tapes to erase and they MUST be clean.
Plus, if you're really the paranoid type, there are certain TLAs (Three Letter Agencies) that supposedly can read data that's been overwritten with rubbish, or new data. Since different tape drives' write heads line up differently, they can sometimes pick up an earlier write along the edges of the recording path.
So, it all gets back to WHY you need to erase the tapes and how critical it is to not be able to read the old data. Also how many to you need to clean. It's a business decision. Cost/Benefit at it's finest.
Hope this helps.
I used to work for a government organization that will remain nameless. Because of security concerns, ALL tapes were required to be degaussed when a certain date had been reached, when it was to be reused, or when a tape was being decomissioned. With a degaussing machine, you can clean a tape in just several seconds without having to mount it, issue commands, and dismount it. That's several seconds verses several minutes. It's well worth it when you have a couple hundred tapes to erase and they MUST be clean.
Plus, if you're really the paranoid type, there are certain TLAs (Three Letter Agencies) that supposedly can read data that's been overwritten with rubbish, or new data. Since different tape drives' write heads line up differently, they can sometimes pick up an earlier write along the edges of the recording path.
So, it all gets back to WHY you need to erase the tapes and how critical it is to not be able to read the old data. Also how many to you need to clean. It's a business decision. Cost/Benefit at it's finest.
Hope this helps.
KenCunningham
Technical User
Sam, thanks for that. I too used to work for a Government Department (who shall remain nameless but presided proudly over the Foot and Mouth fiasco) with the occasional requirement for degaussing of tapes (possibly to hide where the bodies/carcasses were buried ;-) ), so I do see where you're coming from. As you say, it's probably for Kems to make his/her mind up about the absolute necessity of this investment.
Annihilannic
MIS
You can also completely destroy some non-linear tape formats using a magnet, so I don't recommend it. ;-)
Annihilannic.
Annihilannic.
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