SCP OR RSYNC

Just wondering if somebody can tell me the pros and cons of SCP and
RSYNC over SSH.

I want to write a script that sync's up two directories between two
systems across the internet, but want to use a product that is secure,
yet flexible. If you have other suggestions besides SCP and RSYNC i'm
all ears and eyes.

Thanks!

On 2005-03-03, pyro <pyro@netmail.com> wrote:
> Just wondering if somebody can tell me the pros and cons of SCP and
> RSYNC over SSH.

From a security standpoint, there is not a whole lot of difference. scp
and rsync-over-ssh will be more-or-less [0] equally secure.

--keith

[0] rsync-over-ssh might send less data over the wire, foiling any
potential attack that requires lots of data to obtain some sort of
pattern. The truly paranoid will consider this factor, but for most
purposes it's probably not an issue.

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pyro <pyro@netmail.com> writes:

> I want to write a script that sync's up two directories between two
> systems across the internet, but want to use a product that is
> secure, yet flexible. If you have other suggestions besides SCP and
> RSYNC i'm all ears and eyes.

Have a look at unison, it can be used with ssh.
http://www.cis.upenn.edu/~bcpierce/unison/


tom

--
as seen in a signature:
"In an open world without walls and fences,
who needs Gates and windows?"

pyro <pyro@netmail.com> writes:

>Just wondering if somebody can tell me the pros and cons of SCP and
>RSYNC over SSH.

>I want to write a script that sync's up two directories between two
>systems across the internet, but want to use a product that is secure,
>yet flexible. If you have other suggestions besides SCP and RSYNC i'm
>all ears and eyes.

Use rsync. It is for precisely your purpose. And it uses ssh as the
connection protocol. And it only tranfers those things which are actually
different rather than transfering everything each time.

unruh@string.physics.ubc.ca (Bill Unruh) writes:

> pyro <pyro@netmail.com> writes:
>
>>Just wondering if somebody can tell me the pros and cons of SCP and
>>RSYNC over SSH.
>
>>I want to write a script that sync's up two directories between two
>>systems across the internet, but want to use a product that is secure,
>>yet flexible. If you have other suggestions besides SCP and RSYNC i'm
>>all ears and eyes.
>
> Use rsync. It is for precisely your purpose. And it uses ssh as the
> connection protocol. And it only tranfers those things which are actually
> different rather than transfering everything each time.

In theory. It happened to me few times that, if I don't specify '-c'
option, that the rsynced files would be different from the
originals. Luckily I did md5sum on them ...

I also have a case or two of copying 2GB file which was about 50% the same
as the file to be copied to, where rsync took about 45 minutes whereas scp
only took about 20 minutes.

That said, I still use rsync for syncing, but try to add '-c' option any
time that matter.

Dragan

--
Dragan Cvetkovic,

To be or not to be is true. G. Boole No it isn't. L. E. J. Brouwer

!!! Sender/From address is bogus. Use reply-to one !!!

The world rejoiced as pyro <pyro@netmail.com> wrote:
> Just wondering if somebody can tell me the pros and cons of SCP and
> RSYNC over SSH.
>
> I want to write a script that sync's up two directories between two
> systems across the internet, but want to use a product that is secure,
> yet flexible. If you have other suggestions besides SCP and RSYNC i'm
> all ears and eyes.

Unison is another option which is actually aware of the notion that
file transfers might take place in two directions.
--
let name="cbbrowne" and tld="gmail.com" in name ^ "@" ^ tld;;
http://linuxfinances.info/info/slony.html
"Most management-speak is, as Schrijvers points out, Panglossian
balderdash designed to lull the weak and credulous -- the
feeble-minded, the nice into a position of supine docility."
-- Daily Telegraph

unruh@string.physics.ubc.ca (Bill Unruh) wrote:
> pyro <pyro@netmail.com> writes:
>
>>Just wondering if somebody can tell me the pros and cons of SCP and
>>RSYNC over SSH.
>
>>I want to write a script that sync's up two directories between two
>>systems across the internet, but want to use a product that is secure,
>>yet flexible. If you have other suggestions besides SCP and RSYNC i'm
>>all ears and eyes.
>
> Use rsync. It is for precisely your purpose. And it uses ssh as the
> connection protocol. And it only tranfers those things which are
> actually different rather than transfering everything each time.

rsync does a one-way synchronization, causing "Destination B" to
become identical to "Source A".

Unison does two-way synchronization, allowing files to be updated on
either side and be synchronized in whichever direction is appropriate.
--
select 'cbbrowne' || '@' || 'gmail.com';
http://linuxdatabases.info/info/emacs.html
Black holes are where God divided by zero.

"Christopher Browne" <cbbrowne@acm.org> wrote in message
news:38q53eF5qks2aU2@individual.net

>>> Just wondering if somebody can tell me the pros and cons of SCP and
>>> RSYNC over SSH.
>>
>>> I want to write a script that sync's up two directories between two
>>> systems across the internet, but want to use a product that is
>>> secure, yet flexible. If you have other suggestions besides SCP
>>> and RSYNC i'm all ears and eyes.
>>
>> Use rsync. It is for precisely your purpose. And it uses ssh as the
>> connection protocol. And it only tranfers those things which are
>> actually different rather than transfering everything each time.
>
> rsync does a one-way synchronization, causing "Destination B" to
> become identical to "Source A".
>
> Unison does two-way synchronization, allowing files to be updated on
> either side and be synchronized in whichever direction is appropriate.

Thank You. http://www.cis.upenn.edu/~bcpierce/unison/ is a much-welcomed
tool.

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