Suggestion for CD filesystem for Backups

Suggestion for CD filesystem for Backups

[Judith und Mirko Kloppstech]

You can use CDs or DVDs for Backup purposes. They do error correction, 
everything is fine, until the errors get too much, than everything is 
lost. This is a nuisance for a backup, especially because normal people 
don't have the hardware to measure errors, jitter and the like.

Suggestion:
Why not write a file system on top of ISO9660 which uses the rest of the 
CD to write error correction. If a sector becomes unreadable, the error 
correction saves the data. Besides, a tool for testing the error rate 
and the safety of the data can be easily written for a normal CD-ROM drive.

The data for error correction might be written into a file so that the 
CD can be read using any System, but Linux provides error correction.

Mirko Kloppstech

Re: Suggestion for CD filesystem for Backups

[Alan Cox]

On Iau, 2004-09-23 at 00:04, Judith und Mirko Kloppstech wrote:
> Why not write a file system on top of ISO9660 which uses the rest of the 
> CD to write error correction. If a sector becomes unreadable, the error 
> correction saves the data. Besides, a tool for testing the error rate 
> and the safety of the data can be easily written for a normal CD-ROM drive.
> 
> The data for error correction might be written into a file so that the 
> CD can be read using any System, but Linux provides error correction.

Send patches, or possibly if you are dumping tars and the like just
write yourself an app to generate a second file of ECC data.

Re: Suggestion for CD filesystem for Backups

[Erik Hanson]

On Thu, 23 Sep 2004 01:04:00 +0200, Judith und Mirko Kloppstech
<jugal@gmx.net> wrote:
> The data for error correction might be written into a file so that the
> CD can be read using any System, but Linux provides error correction.

You may want to look at parchive, if you havn't already. It does this, is cross-
platform and is in wide use. http://parchive.sourceforge.net/

Re: Suggestion for CD filesystem for Backups

[Ali Bayazit]

On Thu, 2004-09-23 at 17:16 +0100, Alan Cox wrote:
> On Iau, 2004-09-23 at 00:04, Judith und Mirko Kloppstech wrote:
> > Why not write a file system on top of ISO9660 which uses the rest of the 
> > CD to write error correction. If a sector becomes unreadable, the error 
> > correction saves the data. Besides, a tool for testing the error rate 
> > and the safety of the data can be easily written for a normal CD-ROM drive.
> > 
> > The data for error correction might be written into a file so that the 
> > CD can be read using any System, but Linux provides error correction.
> 
> Send patches, or possibly if you are dumping tars and the like just
> write yourself an app to generate a second file of ECC data.
> 
Wouldn't it be safer to do ECC on meta-data also?
That probably means replacing ISO9660 though.

-ali

-- 
Ali Bayazit <listeci@bayazit.net>

Re: Suggestion for CD filesystem for Backups

[Toon van der Pas]

On Fri, Sep 24, 2004 at 01:18:19AM -0400, Ali Bayazit wrote:
> 
> On Thu, 2004-09-23 at 17:16 +0100, Alan Cox wrote:
> > On Iau, 2004-09-23 at 00:04, Judith und Mirko Kloppstech wrote:
> > > Why not write a file system on top of ISO9660 which uses the rest of the 
> > > CD to write error correction. If a sector becomes unreadable, the error 
> > > correction saves the data. Besides, a tool for testing the error rate 
> > > and the safety of the data can be easily written for a normal CD-ROM drive.
> > > 
> > > The data for error correction might be written into a file so that the 
> > > CD can be read using any System, but Linux provides error correction.
> > 
> > Send patches, or possibly if you are dumping tars and the like just
> > write yourself an app to generate a second file of ECC data.
> 
> Wouldn't it be safer to do ECC on meta-data also?
> That probably means replacing ISO9660 though.

There seems to be a good user space alternative for this purpose:

	http://dvdisaster.berlios.de

Regards,
Toon.
-- 
"Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it." - Brian W. Kernighan