[mdlug] Compression and Archiving

[Aaron Kulkis]

Drew wrote:
> I find myself with a lot of data to archive and back up - 120 GB of 
> it, with possibly more to come at a
> later date - and am considering DVDs and squashfs. Current DVD cost 
> weighs in at 18 cents a disk
> (Office Max), which is under 4 cents a gigabyte, which is less than 
> half the cost of current terabyte
> range hard drives as far as I know.
> 
> Still, before committing resources to this I thought it a good idea 
> to consult the list on a couple of things.
> 
> Squashfs seems to give me compression down to from 66% to 77% of 
> original size with most of the
> files being PDFs. I had been hoping for something a bit better. Is 
> there a way to specify better compression
> methods? Is there a better filesystem to use? Or would I be better 
> off using something like gzip or bz2?
> I'd like to be able to mount these as loop devices.
> 
> Also, can an entire DVD be a squashfs filesystem? Or does it have to 
> be wrapped in an iso?

When ARCHIVING, the last thing you want is compression.
a 1-bit error can cause horrendous data loss.

And with burning DVD's... burning a DVD is literally
very heat-intensive (laser on it's highest setting).
Burning a bunch of DVD's, one after another, is a sure
way to shorten the lifespan of you DVD drive.

Buy a 250 - 500 GB disk (I find 2.5" laptop drives to
be the most convenient form factor for this) and put
it in an external USB case (E-sata is more expensive,
and with archives, controlling costs tends to be more
important than speed).