Gregory K. Ruiz-Ade wrote: > On Oct 3, 2006, at 8:12 PM, kelsey hudson wrote: > >> So, if you have any intention of reusing the tape, keep the bulk >> eraser away! But, as far as blasting the data is concerned, yes, a >> bulk eraser is the way to go if you want to make sure nobody ever >> reads that tape again. :) > > I am reasonably certain that there is nearly not so much information on > a tape that makes it useable as you claim. Tracks, block markers, etc. > are written to the tape by the drive as it lays down the data, to make > it easier to read the data back. The drives are more than capable > enough to write data unguided (they are precision machines, after all.) > > I, personally, have not had problems reusing tapes that have had a visit > to the bulk eraser (also known as a demagnetizer in the machine-tool > industry, used to demag parts after going on the grinders, which use > electromagnets as the work tables.) This was with DAT and 8mm tapes > (and numerous QIC formats.) > > Now, putting a hard drive through a bulk eraser is a great way to render > it useless. >
It is my understanding that LTO media uses magnetic servo tracks applied (only) at the factory. Bulk erase definitely makes it unusable. DAT tapes, I'm not sure. I think some used magnetic servo tracking, some optical (on the non-mag side). I've also heard that on the DAT tapes that are bulk-erasable, you have to have a seriously powerful bulk eraser. Hobby-shop kind probably don't do a good job. The best advice is to check the tape drive manufacturer's manual. I think they all have online resources. Regards, ..jim -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
