rsync/incementral

[Ashley Aitken]

Hi Steve (et al.),

On 31/07/2007, at 9:46 AM, steve harley wrote:

> they whom i call Ashley Aitken wrote:
>> On 31/07/2007, at 12:41 AM, steve harley wrote:
>>> a can't find a single mention of hard links in the RxyncX docs ...
>> Sorry,  I haven't got time to search the docs.   Google get this:
>> <http://www.macosxhints.com/article.php?story=2006051913572885>
>
> i still see no evidence that RsyncX implements the hardlink scheme;  
> i've used it a fair amount, but thought i might have missed this  
> feature; all it does as far as i know is add a GUI and some  
> scheduling assistance to rsync

Yes, and not the best GUI in the world, but it does make it easier  
for some to work out the myriad of options on rsync.  As well, as  
noted below it uses a version of rsync that is HFS+ aware (although  
this may be a historic thing in that MacOSX's included rsync may also  
now do that).

 From the article on macosxhints:

> I had this idea of versioned backups with hardlinks, and I was  
> looking for a tool that used this technique -- which rsync does.  
> rsync is a unix tool that can mirror directories, or whole file  
> systems, to other directories, other file systems, and even over  
> the network. The rsync that comes with Mac OS X isn't HFS+-aware,  
> though -- it won't copy resource forks. And it requires a good  
> amount of manpage reading and command line fiddling to have it do  
> what you want to.
>
> Enter RsyncX. First, it provides you with an rsync version that  
> will copy resource forks. Second, it comes with a neat graphical UI  
> where you just have to point and click to tell it what you want,  
> and it will produce a shell script that does just that. It can even  
> set up a cron job for you that will execute your backup script  
> every night, or whenever you want to. There are some things you  
> should know, though, to make it work as it should.


>>> <http://www.nongnu.org/rdiff-backup/features.html>
>> I remember looking at that as well but I am not sure how it can  
>> provide complete incremental backups without using hard links (if  
>> complete backups are a requirement).
>
> hmmm, define "complete"?

I didn't know how to say "it gives you the full the backed up  
directory structure in each incremental backup without taking up the  
space of another full copy of the backed up directory structure."

> rdiff-backup provides incremental backups with the current full  
> version (mirror) immediately available and a mechanism to retrieve  
> previous versions via a diff

As I said, I thought rdiff-backup was a good option too.  I guess it  
only provide a full version of the current backed-up directory  
structure.  Rsync(X) provide a full version for each backup.

I hope that makes things clearer (as mud).

Cheers,
Ashley.