[ale] Versioning backup solution

[Jim Popovitch]

Stephen, 

Thank you for this info, I have successfully been able to make good use
of it.  Thanks!

-Jim P.

On Thu, 2005-07-28 at 00:58 -0400, Stephen Cristol wrote:
> On Jul 28, 2005, at 12:16 AM, Jim Popovitch wrote:
> > I presently use rsync over ssh to remotely backup a few systems.   I am
> > looking to switch to a secure remote versioning backup system, the
> > perfect one would be a combination of cvs and rsync.  Any ideas or
> > suggestions?
> 
> I currently use rsync to remotely backup some userspace data. I've been 
> experimenting with using additional rsync features (requiring rsync 
> 2.6.1 or later) to preserve previous backups. In a nut shell, after 
> doing a first backup, that is named with a timestamp. I then create a 
> symbolic link named ".previous" to the that data set. Subsequent 
> backups with rsync have the following additional options:
> 
>      --delete --link-dest=$path/.previous
> 
> where $path is the directory where this set of backups are stored. If 
> the backup is successful, ".previous" is repointed, logs are updated, 
> etc.
> 
> These options cause rsync to create a new backup that is an increment 
> relative to ".previous". Files in the previous backup that have not 
> changed are created in the new backup as links (real links, not 
> symbolic links) to the files in the previous backup (--link-dest). 
> Files that no longer exist in the source are not copied or linked in 
> the new backup (--delete).
> 
> The end result is a collection of directories in $path named with 
> timestamps indicating when that backup occurred. I've got a script that 
> mostly does this, but it still has some rough edges.
> 
> Upsides to this approach:
> 
> - all the security of rsync
> - the efficiency of rsync in determining what to transfer
> - efficient storage of native file formats
> 
> Downsides to this approach:
> 
> - this can create an enormous number of links and I know of no tools to 
> manage them easily (e.g., if you want to prune the data set)
> - managing disk space becomes more challenging ("du" still gives 
> correct answers; if you ask the right questions, they can be useful 
> answers, too)
> 
> S
>