[CentOS] rsync question

Thu Sep 10 00:17:24 UTC 2015
Carl E. Hartung <carlh04426 at gmail.com>

On Wed, 9 Sep 2015 05:51:38 -0700 (PDT)
Mark Milhollan wrote:

> On Tue, 8 Sep 2015, Carl E. Hartung wrote:
> >On Tue, 8 Sep 2015 10:25:33 -0700 (PDT) Mark Milhollan wrote:
> >> -e specifies the *local* transport command to use
> >
> >What?! Straight from the documentation:
> >
> >"       -e, --rsh=COMMAND           specify the remote shell to use"
> If only one can properly interpret the meaning...  COMMAND is the
> local command to run to obtain a remote (non-interactive) shell, so
> it isn't that the remote shell program (invoked once the transport is
> connected) is being specified, i.e., it is which `remsh' to use.  The
> -p and -l provided thereby may be necessary, since the one is not the
> default and the other isn't known to us to be the same as the local
> user, which you glossed over as if one never has a need to specify.
> Orthogonal to Robert's problem, the switch from default use of rsh to 
> ssh has made it a requirement for (good) automation to always supply
> a -e to ensure the correct command is used to account for all
> potential versions of rsync that may be used.
> >> , and in this case it also specifies the remote port (613) and user
> >> (root).  Granted one should probably use their ssh configuration to
> >> do that but it isn't realy "wrong" (to be questioned) to do it via
> >> options.
> >
> >I didn't explicitly state that it was "wrong," just implied
> >(correctly) that it was unnecessary.
> Potentially unnecessary.  Just because you might see putting the port 
> and user in the ssh config file as the right thing to do, and which I 
> also do whenever possible, doesn't mean Robert necessarily wants to
> or can do so, and after all -e does exist.  Your questioning its use
> as you did implied using it is wrong, to which I object.  Luckily you
> decided to reply to the list quoting me so eventually Robert was
> supplied with the clue you didn't provide, that it might be
> pre-configured.
> /mark

Mark, I would prefer it if you would please send your replies to the
list and not to me personally. I *do* get them if you send them to the

All of these fine grained points you've made regarding options that are
"required for (good) automation" are irrelevant. Robert's post
concerned invoking rsync manually "for backup purposes" -- not for
"automation" as you're envisioning. He wrote "This is not an automated
system.  It is typically a onetime thing ..."

Moreover, my "Why '-e'?" query was paired with a second very specific
question: "Are these systems running disparate operating systems?" The
implication seems pretty clear to me -- not that '-e' was somehow
"wrong" but simply likely unnecessary in his scenario. I stand by that
somewhat informal (less strict than you) evaluation unless and until we
learn that he's actually operating on truly disparate systems.