Re: [Duplicity-talk] A couple easy questions

[Travis H.]

A word to the wise; this list is not very active, so you may have
to wait a while before being answered.

I don't actually use duplicity (yet), but I can answer a few things.

On Sat, Dec 30, 2006 at 10:08:24AM -0800, mike wrote:
> 3. I haven't seen it specified but the archives are compressed using
> gzip, correct? Not just tar+gpg, but tar+gzip+gpg? The compression
> could happen during the GPG encryption too I suppose, I just want to
> make sure that my archives are being compressed, using -9 (best
> encryption) if possible. I don't see any switches to disable
> compression or to change the compression ratio.

If it used bzip2, you could set BZIP envar and specify -9.

I think gzip should really have something like it.  If you feel like
emailing them with that suggestion, have at it.  Or just patch your
duplicity to use bzip2; it gives better compression anyway.

> 4. Is there a way to disable deltas and transfer the whole file if a
> file has changed? Not do a "full backup" but just a full copy of the
> file. That could be useful (especially if things like corruption can
> break or confuse a delta enough to wreck the previous versions)

I think this is handled adequately with rsync, but not sure.
If rsync can detect silent (hardware-level) corruption, then
this isn't a problem.  If it only checks mtime/ctime, you're
right.

Basically, we need end-to-end data protection.  In this case, it makes
sense to do it at the application level, which gives you the fullest
protection - if the OS, network or hardware corrupt it, then you can
detect that fact and do something about it.

I'm thinking of writing a little filter that embeds integrity
checksums in the data in a variety of ways so that you can simply
run it through the filter with some flags and have the protected
data pop out.
-- 
A: No.
Q: Should I include quotations after my reply?
<URL:http://www.subspacefield.org/~travis/> -><-

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