Re: [tlug] rsync vs dd [was Tlug Digest, Vol 14, Issue 23]

["Erin D. Hughes" <erin-hughes@??>]

Evan Monroig wrote:
> On 2/20/07, Erin D. Hughes <erin-hughes@??> wrote:
> > you could use  rsync  with the -z option and that will compress your 
> > data.
>
> As far as I know, the -z option is for compression of the data during
> the *transfer*, not for storage.  So if you rsync between computers it
> is faster, but the space occupied on disk will be the same.
Thanks Evan apparently a little more reading was needed on my part;

-z, --compress
             With this option, rsync compresses any data from the  
files  that
             it  sends  to  the destination machine.  This option is 
useful on
             slow connections.  The compression method used is the same 
method
             that gzip uses.

             Note  this  this  option  typically  achieves  better 
compression
             ratios that can be achieved by using a compressing remote  
shell,
             or a compressing transport, as it takes advantage of the 
implicit
             information sent for matching data blocks.


"With this option, rsync compresses any data from the  files  that it  
sends  to  the destination machine." Says it all. This also cleared up 
my misunderstanding of what a compression format is being used,  "The 
compression method used is the same method that gzip uses."

Could someone suggest the correct method to copy from one place to 
another and achieve a compressed file in the end?


Erin D. Hughes 
GMO Internet,