[lbackup-discussion] lBackup and Symbolic Links

[Michael Williams]

Ok  thanks Scott.

I might put it in the too hard basket for this install. I will just  
put all the files into one folder and backup the folder. Not as nice,  
but it will do the trick.
It's a real shame that lBackup can't backup multiple source  
directories as one backup script.

Thanks anyway,

Michael

On 23/01/2010, at 3:42 PM, Scott Haneda wrote:

> On Jan 22, 2010, at 6:19 PM, Michael Williams wrote:
>
>> I am doing yet another install of lBackup, but I wanted to do  
>> things differently this time (since the data and the OS will reside  
>> on the same volume).
>> I remember reading somewhere that lBackup follows Symbolic links,  
>> so I thought I would be clever and create a folder full of symbolic  
>> links to the folders I want to backup. I tested this by creating a  
>> symbolic link using the ln -s command in the terminal. The link  
>> created ok, and it seams to work in the terminal because if you use  
>> the link as part of the cd command you end up in the right place. I  
>> then tried to get lBackup to backup the folder with the symbolic  
>> link in it to another folder on the hard drive. The backup  
>> proceeded without error but lBackup only copied what looks like an  
>> alias to the original file which is not what I was after.
>>
>> Does anyone have any ideas what is happening? Should this work or  
>> did I misunderstand?
>> For the record, I have compiled rsync 3.0.7 and patched according  
>> to Mike Bombich's instructions (obviously substituting the version  
>> numbers). Has anyone else had experience with this new version of  
>> rsync?
>
> You need to make sure to use archive mode in rsyc, which is the  
> backend that drives lBackup.  From the rsync man page:
>
>    SYMBOLIC LINKS
>
>    Three basic behaviours are possible when rsync encounters a  
> symbolic link in
>    the source directory.
>
>    By default, symbolic links are not transferred at all.
>    A message "skipping non-regular" file is emitted for any symlinks  
> that exist.
>
>    If --links is specified, then symlinks are recreated with the  
> same target
>    on the destination. Note that --archive implies --links.
>
>    If --copy-links is specified, then symlinks are "collapsed" by  
> copying their referent,
>    rather than the symlink.
>
> you need -a or --archive
> I think there is also a shortcut that combines a number of modes to  
> help in doing just what you want to do.  I can not remember it off  
> the top of my head. The Carbon Copy Cloner info pages speaks of it.
>
> Pay special attention to:
> -x, --one-file-system       don't cross filesystem boundaries
>
> That flag can bite you pretty hard if you are trying to clone an  
> entire system, so for example:
> rsync --whatever / /Volumes/second-drive/backups
>
> You can end up in a perpetual and recursive copy, where rsync will  
> follow whatever in in /Volumes, but loop around on itself and do it  
> again and again.  I filled up a 1TB drive when I walked away for a  
> few hours.  I had a few other things on the drive so I was not able  
> to just reformat it.  It took ages to `rm` all the files.
>
> Just make sure you use explicit paths to your Volumes, and that you  
> exclude known locations that wrap around on themselves.
>
> I think you may want to skip the symbolic link idea, and just call  
> out explicitly the pats that you want to backup.  I believe that is  
> the general idea that lBackup want you to work under.  Though I  
> could be wrong, and hope an admin will correct me if I am.
>
> -- 
> Scott * If you contact me off list replace talklists@ with scott@ *
>
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