possibly lost data by "Burning Raw Data CDs"

[Lowell Gilbert]

"dcswest at flashmail.com" <dcswest at flashmail.com> writes:

> Was running FreeBSD 5.1 Release on a Dell Inspiron 8500 with
> a CD-RW/DVD Combo drive and "backed up" data onto several
> new CD-RWs simply as follows:
> 
> burncd -s max data archive.tar.gz
>
> Then after installing FreeBSD 5.2 Release, tried restoring
> as follows:
> 
> tar -xvzf /dev/acd0
> 
> And unfortunately ended up with only error messages such as
> input/output, unexpected end of archive/file and child
> returned status 2 from all the CD-RWs too.

The block size on a CD is 2048.  You need to tell that to tar.
I think you can do it with the -b option.
Fixating would definitely be a good idea, in any case; I'm not sure
it's necessary, but I would expect it to be.

> Not sure if it has anything to do with not blanking or
> erasing the new CD-RWs first or not adding "fixate" to the
> "burncd" command, but planning to always now just burn and
> thoroughly test ISOs for even one file, and only desperately
> seeking to first recover this data any which way.

dd if=/dev/acd0c of=archive.tar.gz bs=2048

You shouldn't need to do that, but it won't really hurt either, aside
from a small space wastage.

Whatever you do, though, TEST YOUR BACKUPS BEFORE YOU NEED THEM.