Re: [Duplicity-talk] A few Q's about duplicity compared rsync

[Will McCown]

On 12/25/2013 5:46 PM, Pedro Ribeiro wrote:
> Hi,
> 
> I'm a long time rsync user which has just started using duplicity for
> encrypted remote backups to Google Cloud.
> There are a few questions for which I couldn't get an answer in the
> docs, or maybe my understanding of duplicity is wrong.
> 
> - I only backup my home directory with incremental rsync backups. Is
> there a reason for not doing a full backup once with duplicity and
> then incremental forever? The docs are a bit ambiguous about this, and
> reading around the web it seems some people are keen on doing full
> backups every now and then. Is there really a necessity (some kind of
> bit / backup rot)?

It comes down to how much pain you are willing to deal with if
you should ever have to do a full restore, since a restore will
require reading the full backup plus every incremental done since.
The docs are ambiguous about this because the best choice
depends strongly on how much the data being backed up is changing.
For my own use (which is primarily my email folders) I do daily
backups with "--full-if-older-than 1M".  I also periodically run
the "remove-all-inc-of-but-n-full 2" command on my backup to clean out
the incremental backups on the older sets.

> - I used to run rsync with the --delete option. This would mean that
> if a file in the backup target had been deleted / wasn't present in
> the backup source, it would get deleted. Does duplicity does the same
> thing automatically, or should I be passing "--delete" to
> --rsync-options?

There is no equivalent to "--delete", the deleted file will remain
in the backup until you decide to do a new full backup and remove
the old full and incremental backups.  In planning your backup strategy
keep in mind that files do sometimes get accidentally deleted, and
I know I've done it and not noticed the file missing for weeks or
months.

If you are used to using the rsync "--link-dest=" flag to create
time machine style snapshots of your home directory, you need to
understand that duplicity works quite differently.

-- 
Will McCown, Rolling Hills Estates, CA
address@hidden