Question on --backup --backup-dir Switches For Incremental Backs

[Paul Slootman]

On Mon 29 Jan 2007, Blake Carver wrote:

> I current do some rsync backups with a command like so every day
> 
> rsync -az -e ssh --stats --delete --exclude "stuff" / 
> user at server:/home/user/
> 
> What I want to do is have some incremental backups in there in
> subdirectories. So, for example, something like this on the remote
> server
> /home/user/something.tuesday
> /home/user/something.friday
> 
> I thought the --backup --backup-dir Switches were used to store just
> the files that had changed in seperate directories, am I wrong on
> that?

You're right on that account.

Why do you want incremental backups?  Things like dirvish or rsnapshot
(I'm not so familiar with rsnapshot) will create complete backups that
don't take that more space than incrementals (the main difference is the
space needed for the directory structure, common files are hard-linked
between versions).  If I then want to restore from a specific day, I
don't have to gather all the incremental versions one after the other,
and that's not taking into account files that have been deleted between
days...

I'd recommend using the --link-dest option.  Start with one day, e.g.
Monday, and then use that as a basis for Tuesday:

rsynz -az --stats --delete --exclude "stuff" --link-dest=../something.monday / user at server:/home/user/something.tuesday/

You may want to also use -H in addition to -a to preserve hardlinks from
the source.


Paul Slootman