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Re: [vox-tech] very burning questions....
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Re: [vox-tech] very burning questions....

On Fri, 22 Sep 2000, Peter Jay Salzman wrote:

> dear all,
> 1. how much data?
> i know a typical CD holds something like 650 or 680 MB.  i also know that
> there's some overhead in the iso9660 filesystem.  so the maximum capacity of
> a cd is uninteresting when compared to "how much of my data can i fit onto a
> cd?".  has anybody done tests to see what this maximum is?

650 is standard, you can also buy 700.
The overhead is usually small relative to the amount of actual data.  The
overhead your talking about is usually associated with "padding" up to
certain sector number that are a multiple of (hmmm... can't remember) some
number.  The more padding you require, the more overhead, so if you had
many very small files, your overhead would increase.  I'd say that if you
had 15 MB of overhead, that would be huge.

> 2. what happens if i go over?
> what happens when i go over this limit?  does the data not get written or
> does the cd become toast?

The answer is that the results are unpredictable.  Clearly the data cannot
exceed the capacity of the disk, but whether or not you've made yourself a
coaster remains to be seen.  There are no size limitations inherent in the
cdrecord program.

> 3. question about man mkisofs
> according to the man page, the -d option: "omit trailing period from files
> that do not have a period".   what the HECK is that supposed to mean?

got me there, it probably means that a period won't be added to files
without extensions.

> 4. about extensions
> so there's the joliet and rockridge extensions.  i'm not considering the el
> torito extension because i'm not terribly interested (yet) in making a
> bootable cd.   which do people use?  what are the advantages/disadvantages
> of each?  i know that joliet allows longer filenames and the rockridge keepsi
> the idea of ownership and permissions on a file.  anything else?  the
> manpage says that rockridge is still bound by 8.3 filenames.

What I gather is rockridge preserves UNIX like attributes (owner,
permissions, etc.) and Joliet is for win32 systems (don't know much about
this).  I've used rockridge and anonymous rockridge without problems with
long filenames.

> 5. about filenames
> according to man mkisofs, the -l option allows you to use 30 character
> filenames instead of the 8.3 specified by iso9660.   do people use this?
> any caveats?  it says the rockridge extensions still mandate an 8.3
> filename.  i definitely want long filenames on my burned cd's.

see above.
> 6. about disks
> do people have a favorite place/supplier for the cheapest high quality CDRW
> disks?  i know enough to not buy them at frys, unless i want to pay more.
> any favorite websites to check out?   also, i've heard that the different
> colours of disks mean differing quality.  is that true?  which colour is the
> highest quality?   is there a difference between CDR and CDRW disks?

If you want bulk, go to pricewatch.com and do some searching.  You should
be able to get CD-Rs/CD-RWs for ~$0.50 or less each.  Also, Fry's and
Costco carry them.
Quality: I have some TDK 700MB CD-Rs that work fine on my machine and 
other computers, and also do well as audio CDs on my home stereo(s), but
don't work in all car cd players.  I've been told that silver and gold are
the best colors for compatibility in players.

If you're not already aware, CDRW's will not work everywhere.  There are
some exceptions, but for the most part they'll only be recognized in
machines with CDRW drives.

> i feel kinda lost about all this, but it's starting to come together.  any
> hints would be really appreciated!

There is a very useful CD-writing HOWTO at:

Also, you may want to check out some burning programs.  I use gcombust,
which is simply a front-end for cdrecord/mkisofs/cdparanoia.  I think it's
great because I don't have to remember all the options, and it has online
docs.  You can find that at freshmeat.

Have fun,
-- Chris

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