lotus

previous page: 3-19] How can I compress or encrypt data on a CD-ROM?
  
page up: CD-Recordable FAQ
  
next page: 3-21] How do I automatically launch something? Change the CD icon?

3-20] Can I do backups onto CD-R?




Description

This article is from the CD-Recordable FAQ, by Andy McFadden (fadden@fadden.com) with numerous contributions by others.

3-20] Can I do backups onto CD-R?

(2001/09/26)

Yes. See section (6-7) for software.

Of course, it's not really necessary to use special software if you're just
backing up your data files. Most CD creation programs will allow you to
copy arbitrary files onto CD-ROM, and by using the Joliet standard or the
UDF filesystem you can preserve long filenames. Unfortunately, if you're
not using packet writing, the individual files may show up as read-only
under DOS and Windows, so write permission must be re-enabled by hand when
the files are restored. With packet writing applications like DirectCD
or PacketCD, the correct file permissions are maintained.

(See section (3-57) for instructions on clearing the read-only flag.)

One thing to be careful of on Windows-based PCs: most programs that put
files on CD don't preserve the *short* file names that are automatically
generated for files with long file names. This presents a problem because
the short form is often stored in the Registry and INI files instead of the
long form (try searching your Registry for "~1"). When your system is
restored, it may not be able to find the files anymore.

A way to work around this is to use a backup program that understands only
the short filenames, and save the long ones with LFNBK. A program called
DOSLFNBK at http://www8.pair.com/dmurdoch/programs/doslfnbk.htm may be more
convenient than LFNBK.


Is CD-R better than, say, DDS-3 tapes? Maybe. Tape formats like DDS and DLT
hold considerably more than a CD-R, but because the drives are streaming
rather than random access, recovery of a specific file can be slower.
For backing up a large system or network, tapes are more convenient.
For making backups of a small system, especially one where access to older
versions of files is frequently desired, CD-R is the better choice.

Some people prefer CD-RW. For daily incrementals, CD-RW makes sense. For
weekly or monthly full backups, you probably want to retain the discs in
case file corruption or deletion goes unnoticed for some time.

The longevity of magnetic tape is well understood (around 15 years for
most formats). The longevity of CD-R is a little harder to quantify.
See section (7-5) for details.


 

Continue to:













TOP
previous page: 3-19] How can I compress or encrypt data on a CD-ROM?
  
page up: CD-Recordable FAQ
  
next page: 3-21] How do I automatically launch something? Change the CD icon?