[ale] Initial RSYNC data validation

[Jim]

attriel wrote:

>James Taylor wrote:
>  
>
>>I've got about 500GB of data I need to maintain a sync of across a WAN connection, and RSYNC seems well suited for what I need to do.  However I have not been able to figure out how to establish an initial sync without copying all the data over the first time.
>>
>>There must be a switch I can use to do a data compare on an initial sync to establish a baseline.
>>
>>Just to be clear, I have a back up of the original data which I restore on the remote site.  I then want RSYNC to know that the files on the remote site are the actual unchanged files that they are comparing from the local site on the initial sync.  I don't want to try to copy all of this across the WAN link.
>>    
>>
>
>rsync starts with comparing the files (chunky md5 i think)
>
>i think the -n switch is "don't copy anything, just tell me what you 
>would do" so you can try that to see what files it thinks don't match
>
>--attriel
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>  
>
       --size-only
              Normally  rsync will not transfer any files that are 
already the
              same size and have the same modification  time-stamp.  
With  the
              --size-only  option,  files will not be transferred if 
they have
              the same size, regardless of  timestamp.  This  is  
useful  when
              starting to use rsync after using another mirroring system 
which
              may not preserve timestamps exactly.

This might help.  It's possible that the time stamps are different, so 
this option will allow you to ignore that.    Combine this with the -n 
option as suggested to see what effect it will have.

Jiml