[EMAIL PROTECTED] writes:
> On Fri, Jul 28, 2000 at 11:05:54AM +0200, Wolfgang Weisselberg wrote:
> > Hi, r.basak!
>
> Hello :-)
>
> > Trying to kill the keyboard, [EMAIL PROTECTED] ([EMAIL PROTECTED])
> > produced 2,1K in 58 lines:
> >
> > > On the other hand, if you want properly secure backups, then you
> > > should encrypt. Get gnupg (http://www.gnupg.org), and get it to use
> > > symmetric encryption through pipes; then you can pipe tar through to
> > > gnupg and then to ftape, encrypting on-the-fly.
> >
> > Remember though that a single bit error can (and probably[1]
> > will) kill all of the backup after the error.
>
> Yes. I don't know about other drives, but the Ditto Max uses ECC, so
> isn't this unlikely? A failure with the ECC on the tape is just as
> likely as a failure of ECC (or whatever other system you use) in [1],
> isn't it?
All floppy tape drive use ECC, and all use the same algorithm (luckily).
Nevertheless data-loss can happen.
The algorithm used by floppy tape drives uses 3kb of ECC information
per 29k of data. Up to 3 bad sectors can be corrected (per segment).
Generally, compression or encryption of the whole backup stream is a
bad idea for backups. Instead, a blockwise compression should be used.
BTW, QIC-113 describes how this could be done (and is probably done by
Windoze software).
Claus
--
Claus-Justus Heine
[EMAIL PROTECTED]
http://www.instmath.rwth-aachen.de/~heine/
Ftape - the Linux Floppy Tape Project
Home Page : http://www.instmath.rwth-aachen.de/~heine/ftape/
Mailing-list: [EMAIL PROTECTED]
