[G4] CD burning questions

[Alex]

On Tuesday, Jun 15, 2004, at 13:34 Canada/Eastern, Keith Whaley wrote:

>  [...] When I take a fresh [new] CD, mount it on my desktop, and load 
> a number of items onto it for safekeeping... and then "burn it", does 
> that essentially lock the CD for any future adding of data?

Yes. What you describe creates a single-session CD (all the data is 
burned in one go), and that's the most common way of writing CDs. It is 
also possible to write multisession CDs (each session appears as a 
separate partition). It's easier to do so with a utility such as Toast, 
but it can also be done with the tools provided with Mac OS X (see 
<http://macs.about.com/cs/osxbasics/a/burn_sessions.htm>). Most CD 
players play only the first session of an audio CD, so multisession is 
only recommended for data. In my experience, some drives have problems 
handling more than one session, so, for maximum compatibility, I only 
use single-session CDs.

It is also possible to write data to CDs in packets (a bit like 
floppies). This is the method used by Retrospect. It requires special 
drivers to write and access, and, to my knowledge, there's never been a 
reliable general use packet driver on the Mac platform. On Win, 
DirectCD is the most common, and it's fairly reliable.

> [...] I've used that drive and CDs for backing up my HD many times in 
> the past, but I just blindly follow what Retrospect tells me [...]

Retrospect's driver is very finicky. From time to time you should check 
the log and verify your back up set, to make sure of its integrity.

> With respect to CD-Rs, once you perform one (the first) write-to 
> exercise, is that IT? [...]

See above. The difference between CD-R and CD-RW is that the latter can 
be erased.

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