Use tar to append?

[Ed Greshko]

Mike McCarty wrote:
> Cameron Simpson wrote:
> 
> [snip]
> 
>> Tar files have a terminating record. To append you need to overwrite
>> that record, and that you can't do in compressed state.
> 
> Fine. How do I get tar actually to append? I can compress later, if
> need be, I guess.
> 
> Perhaps I'm asking amiss.
> 
>> But I must be missing something. Why append to the tar file at all?
>> Why not just make a lot of separate tar files?
> 
> Because I'm using CDROMs with K3b to write them, and I want as
> much on a single disc as possible, without a lot of fiddling
> to find which ones will fit with minimal wasted space. If I
> use a single file, and split it, I get no wasted space at all
> (except on the last disc, which is unavoidable).
> 
> Ok, I'm asking about means rather than goals. Let me restate
> my desires.
> 
> I want to make as few CDROMs as possible, with no wasted space
> (except on the last disc). So I want some kind of compression.
> 
> I want a complete TOC (a la tar tvzf backup.tgz > backup.lst).
> 
> I want progress reports via wall showing what directory is
> currently being worked (top level only, I don't want to know
> details, like /etc, /usr, /home, etc.).
> 
> I want speed, as in not copying gigabyte files tens of times.
> 
> If I can get tar to output progress reports like that via
> wall in more or less real time by other means than by appending,
> I'll be happy. If not, then I'd like a script loop which
> does the walls, and invokes tar multiple times, but only
> if I don't copy gigabyte files tens of times.

Maybe a silly question...but are you doing this for backups?  Just wondering 
why you wouldn't use Amanda.

-- 
You're at Witt's End.