misc aols post

misc aols post

Update: 2010-10-24

Sometimes Google Groups doesn't capture posts, or in this case at least one of their servers did (How else did I get the ref number?). Anyway here it is copied from a long term newsgroup archive:

On Sun, 20 Dec 2009 02:24:34 +0000, no.top.post wrote:
 
> On my old system, I've only just figured out how to backup a tree by:--
> 
> mkisofs -R /mnt/p6/usr/lib  | cdrecord -v fs=6m speed=2 dev=0,0 -
> 
> Obviously I'd rather not have small [10% of CD capacity] dir-trees on
> each CD, so I'd want to serially write several dir-trees to the same
> CD.
> 
> Apparently the above instruction does:
>   AND_THEN 
> So then the 2nd step would start writing from the CD beginning ?
> 
> But this is too simplistic since it's seen from the
> messages-while-running that a fifo is repeatedly written and read.
> 
> So how can I read multiple dir-trees and write them to the CD ?
> 
> == TIA

IME, data written to a CD needs to be "staged" in some way. The staging
directory provides the top-level directory structure for the final CD.
You might be able to rig something different, but I am not aware of how
to do it. Multisession optical may do something _close_ to what you
want. Feel free to experiment, but be prepared to invest some time and
media in making sure it is doing what you want.
 
Here is some additional unsolicited information- FWIW. One size does not
fit all when selecting an appropriate backup strategy. YMMV.
 
I use optical discs as my primary long-term backup medium. Their
durability and  cost vs. capacity remains somewhat competitive when
compared to magnetic devices. However, making an optical disc requires
more time and effort. To minimize the time required, I use a strategy
which stages the backup data from disk-to-disk-to-optical. In my case,
daily snapshots are created automatically, and are allowed to accumulate
in a staging directory. I can simply write them out to optical when
convenient. BTW, because the data is staged, the snapshots can be "post
processed," for example, I use both compression and encryption. When the
final disc image is ready, it is written to optical as a single session,
and then verified. Multiple copies can be made for redundancy and as
necessary.