dvdisaster or QuickPar or etc.: do you use them to secure discs?

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|"Re:Timely article... (Score:3, Informative)                          |
|by WuphonsReach ( 684551 ) on Saturday January 24, 2004 @12:01PM      |
|(#8075344)                                                            |
|TY's (as the other posted commented) are reported to be the best CD-R |
|/ DVD-R that you can get. [. . .]                                     |
|                                                                      |
|In addition you should be looking to add parity/recovery data to your |
|CD-R/DVD-R backup files, which serves two purposes: (a) allows you to |
|verify that the files are still readable and intact (b) allows you to |
|recover damaged files if you have enough recovery data. It allows you |
|to recover from scratches that the underlying ECC was unable to       |
|correct for.                                                          |
|                                                                      |
|The easiest product to use right now is called PAR or PAR2            |
|[sourceforge.net] (I prefer QuickPar). Basically, put all of your     |
|files in a single folder (or zip things up into seperate archive files|
|and put those in a single folder) and then use QuickPar to create     |
|recovery data. For a CD-R, I usually collect around 650Mb of data     |
|together, and then create another 45Mb of recovery data. For DVD-R, I |
|do 4Gb of data and 0.35Gb of recovery data."                          |
|----------------------------------------------------------------------|
says
HTTPS://SlashDot.org/story/04/01/24/0054242/guide-to-digital-preservation-f=
rom-nist

Do you use anything like them?

|----------------------------------------------------------------------|
|"profdredd - 2006-12-24                                               |
|I'd like to use QuickPar, or par2cmdline, to protect archives stored  |
|on CD-R and DVD-R media. Is there a tutorial or FAQ describing in     |
|detail how to do this?                                                |
|                                                                      |
|By "archive" I mean data frozen in permanent storage on optical       |
|discs. I don't mean a "backup" where the data also exists on the PC,  |
|or other media besides optical disc. In this scenario, I feel the     |
|parity recovery capabiltiy provided by Par2 is very valuable.         |
|                                                                      |
|I've read the documentation for QuickPar, but it only covers Usenet   |
|usage. I've also read the tutorials linked from the QuickPar site, but|
|they only cover Usenet usage.                                         |
|                                                                      |
|I've read the forums on the QuickPar site, every single message in    |
|"Using QuickPar with CDRs and DVDRs". The thread which seems most     |
|informative is "QuickPar Media Recovery - My Tests & Techniques", but |
|it doesn't suffice as a tutorial. There doesn't seem to be much       |
|agreement about the best way to use Par2 data on optical media.       |
|                                                                      |
|                                                                      |
|Nobody/Anonymous                                                      |
|                                                                      |
|Nobody/Anonymous - 2008-06-16                                         |
|Have you try DVdisaster?  They are pretty about that, free and        |
|cross-OS."                                                            |
|----------------------------------------------------------------------|
says
HTTPS://SourceForge.net/p/parchive/discussion/96207/thread/7732c181/?limit=
=3D25#
before more answers.

HTTPS://dvdisaster.JCea.Es/downloads/manual.pdf
says:
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|"This is the orange manual, describing the usage of dvdisaster, a tool    =
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|for creating error correction data (=E2=80=9Cecc data=E2=80=9D) for optica=
l media such     |
|as CD, DVD and BD discs. Use cases for creating ecc data, recovering      =
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|defective media using ecc data and for general maintenanance of           =
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|optical media are given. [. . .]                                          =
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|                                                                          =
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|Copyright 2008-2017 Carsten Gn=C3=B6rlich.                                =
      |
|Copyright 2019-2021 The dvdisaster development team.                      =
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|Verbatim copying and distribution of this entire article is permitted     =
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|in any medium, provided this notice is preserved.                         =
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|                                                                          =
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|[. . .]                                                                   =
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|                                                                          =
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|Preface                                                                   =
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|After the publishing of version 0.79.5, the project has been dormant      =
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|for another half decade. As time has passed by, it is foreseeable that    =
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|optical media will become extinct just like floppy discs did long         =
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|ago. Still, it is important to preserve the contents of already           =
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|existing optical media.  Towards this end, we will maintain dvdisaster    =
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|to keep it usable on current hardware and OS versions.                    =
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|[. . .]                                                                   =
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|                                                                          =
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|[. . .]                                                                   =
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|                                                                          =
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|1 Overview                                                                =
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|                                                                          =
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|The challenge: Optical media eventually fail. Optical media               =
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|(CD,DVD,BD) keep their data only for a finite time (typically for many    =
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|years). After that time, data loss develops slowly with read errors       =
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|growing from the outer media region towards the inside.                   =
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|                                                                          =
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|The dvdisaster solution: Archival with data loss                          =
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|protection. dvdisaster complements optical media (,=E2=86=92 supported med=
ia)      |
|with error correction data in a way that they are fully recoverable       =
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|even after some read errors have developed. This enables you to rescue    =
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|the complete data to a new medium.                                        =
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|Error correction data, in short =E2=80=9Cecc data=E2=80=9D, is either adde=
d to the         |
|medium or kept in separate error correction files. dvdisaster works at    =
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|the image level so that the recovery does not depend on the file          =
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|system of the medium. The maximum error correction capacity is            =
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|user-selectable.                                                          =
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|                                                                          =
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|1.1 Common misunderstandings about dvdisaster                             =
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|                                                                          =
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|Before we describe in detail what dvdisaster can do, let=E2=80=99s first  =
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|clarify what it can=E2=80=99t:                                            =
         |
|                                                                          =
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|dvdisaster can not make defective media readable again. Like a            =
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|conventional backup, error correction data must be created from a         =
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|fully functional optical medium - you can not backup data which has       =
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|already been lost. When the optical medium develops defective sectors     =
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|at a later time, those defective sectors are restored by                  =
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|re-calculating them from the ecc data. This won=E2=80=99t make the defecti=
ve       |
|medium working again, but will produce a new iso image which can be       =
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|written to a new medium.                                                  =
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|As said before, ecc data can not be created from already defective        =
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|media. Although unreadable sectors can not be recovered in that case,     =
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|dvdisaster might still be helpful in extracting the remaining readable    =
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|portions of the medium.                                                   =
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|                                                                          =
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|[. . .]                                                                   =
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|                                                                          =
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|BDXL-R                                                                    =
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|=E2=80=A2 Currently only the three-layered (100GB) version is tested and s=
upported.|
|=E2=80=A2 Note: BDXL is not backwards compatible with standard BD drives. =
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|                                                                          =
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|Not usable types (image can not be extracted):                            =
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|=E2=80=A2 BD-ROM (pressed BDs), DVD-ROM (pressed DVDs), CD-Audio and CD-Vi=
deo.     |
|                                                                          =
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|[. . .]                                                                   =
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|                                                                          =
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|Q 3.5: My self-written media is recognized as =E2=80=9CDVD-ROM=E2=80=9D an=
d rejected.      |
|The medium book type has probably been set to =E2=80=9CDVD-ROM=E2=80=9D. T=
ypically, a      |
|drive capable of writing the same media format is required for            =
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|processing the medium with dvdisaster.                                    =
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|For example, a two-layered DVD+R with a wrong book type may only be       =
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|accepted on a writer which can write to such media. Try another drive     =
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|for reading images in these cases."                                       =
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|--------------------------------------------------------------------------=
-|

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|"Nobody/Anonymous - 2006-07-22                                     |
|Is there any point in using par for insurance for CDs for data and |
|system backups? Involves a wild variety of file sizes and directory|
|structures. Would it be as easy as just making 3 CD copies for each|
|required, using an expensive brand of course (how else can you tell|
|which really have 'long life')?  When CDs fail, typically, does the|
|whole become inaccessible, or is it file-by-file?                  |
|                                                                   |
|Ol' Bab"                                                           |
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says
HTTPS://SourceForge.net/p/parchive/discussion/96207/thread/b235af8b/?limit=
=3D25#9173/8fa4
before many responses.

Thanks in advance for feedback!
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