Re: [Duplicity-talk] Concurrently running duplicities?

[Andreas Schildbach]

Kenneth Loafman wrote:

> > I'm thinking of this, because I'd like to do incremental backups every 
> > hour, and full backups once a month (or maybe a week). Unfortunately, 
> > a full backup lasts much more than an hour, so doing a full backup and 
> > an incremental backup would overlap each other.
>
> I would not try this.  Incremental backup requires information from the 
> full backup in order to process the change list.  If the full backup is 
> not complete, it could confuse the incremental in one of three ways:

In this case, may I suggest a new feature: Automatically starting a full 
backup after a defined time span. E.g. "--full-backup-every 1M" would 
force a full backup when the last full backup is older than one month 
(or not existing). The default behaviour could indicate "forever", which 
is the current behaviour.

With this feature, the responsibility for not starting two instances of 
the backup process at the same time could be easily assigned to a cron 
implementation without any wrapper scripts.

> Besides, with disk
> reliability the way it is, daily incremental is sufficient.

Well, it could happen that full backups take longer than a day... better 
have a bullet proof solution to this problem, rather than just "hoping" 
processes will never overlap.

Regards,

Andreas