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Re: Questions about rsync

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Spyridon Metaxas wrote:
> 	An rsync client can specify a number of options to shape the file 
> synchronization that it launches. One of those options is compression. 
> Two questions on this:
>
> 	1. When rsync is launched over SSH, is this option passed down to 
> the SSH transport, or is it totally independent? If the latter, we could 
> have compression at the rsync protocol, and then compression at the SSH 
> transport, right? This is probably not a good idea, but I am just 
> interested to learn how things are done in this respect.

It's possible to try (IIRC) -- but yes, doubly-compressing just burns
cpu cycles for the most part.

>
> 	2. Is the server allowed NOT to honor the compression request 
> from the client? Again, taking SSH as a reference - it's just that I am 
> more familiar with it than with rsync - the server is allowed to ignore a 
> compression request from the client. Is an rsync server allowed to do so 
> as well, or is it the case that the synchronization can't succeed if the 
> server, for whatever reason, does not support compression?

as far as I am aware, no.  Remember that the compression is merely
on-the-fly, somewhat equivalent to 

  tar -czvf -- list-of-files | nc server.com portno 

  (server) nc receive | tar -xf --


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Questions about rsync Spyridon Metaxas <SMet@somewhere.world> - 2019-06-24 15:02 +0000
  Re: Questions about rsync Dan Purgert <dan@djph.net> - 2019-06-24 15:08 +0000
  Re: Questions about rsync Grant Taylor <gtaylor@tnetconsulting.net> - 2019-06-24 09:09 -0600

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