Pros and Cons of using ftp vs. rsync?

Assuem I want to transfer large amounts of stuff from one server to another (through Internet).

Which method should I prefer:

ftp or rsync ?

What are the Pros and Cons?

Which is faster?

Which is more stable?

Goran

Goran Ivanic wrote:
> Assuem I want to transfer large amounts of stuff from one server to another (through Internet).
>
> Which method should I prefer:
>
> ftp or rsync ?
>
> What are the Pros and Cons?
>
> Which is faster?
>
> Which is more stable?
>
> Goran

It depends.

If you need to send a lot, and none of it exists at the far end, then
ftp will be faster. ftp just needs to transfer the files, with no
overhead checking what versions exists at each end.

My guess is ftp will be faster. It just moves the files, and does not
care whether they exist on the other end or not.

However, if a large number of files to be transfered already exist at
the far end, then rsync will be faster as it needs to transfer less data.

At 03 May 2008 12:52:33 GMT goran@lycos.com (Goran Ivanic) wrote:

>
> Assuem I want to transfer large amounts of stuff from one server to another (through Internet).
>
> Which method should I prefer:
>
> ftp or rsync ?
>
> What are the Pros and Cons?
>
> Which is faster?
>
> Which is more stable?

Ftp is not secure. I would not use it to transfer large amounts of stuff
from one server to another, unless what you are doing is something like
mirroring a ftp site. If you are planing to provide a mirror to a ftp
site, you should talk to the sysadmin of the site you are mirroring.
They probably have a rsync server in place for this purpose.

Otherwise...

Using rsync over ssh (rsunc -e ssh ...) or using tar over ssh (tar czvf -
-C sourcedir files | ssh othermachine tar xzvf - -C destdir) are both
good options. I'd use the tar/ssh route if this is a new / first time
transfer. Using rsync is better if it is an update (some random subset
of files need to be transfered).

>
> Goran
>

--
Robert Heller -- Get the Deepwoods Software FireFox Toolbar!
Deepwoods Software -- Linux Installation and Administration
http://www.deepsoft.com/ -- Web Hosting, with CGI and Database
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Dave <foo@coo.com> writes:

>Goran Ivanic wrote:
>> Assuem I want to transfer large amounts of stuff from one server to another (through Internet).
>>
>> Which method should I prefer:
>>
>> ftp or rsync ?
>>
>> What are the Pros and Cons?
>>
>> Which is faster?
>>
>> Which is more stable?
>>
>> Goran

>It depends.

>If you need to send a lot, and none of it exists at the far end, then
>ftp will be faster. ftp just needs to transfer the files, with no
>overhead checking what versions exists at each end.

>My guess is ftp will be faster. It just moves the files, and does not
>care whether they exist on the other end or not.

On large files that is a trivial overhead. rsync can also checks if the
files transfered are the same or not. ftp does not
From man rsync
Note that rsync always verifies that each transferred file was
correctly reconstructed on the receiving side by checking its
whole-file checksum,...

>However, if a large number of files to be transfered already exist at
>the far end, then rsync will be faster as it needs to transfer less data.

In comp.os.linux.networking Unruh <unruh-spam@physics.ubc.ca>:
> Dave <foo@coo.com> writes:

>>Goran Ivanic wrote:
>>> Assuem I want to transfer large amounts of stuff from one server to another (through Internet).

>>> Which method should I prefer:

>>> ftp or rsync ?
[..]

>>My guess is ftp will be faster. It just moves the files, and does not
>>care whether they exist on the other end or not.

> On large files that is a trivial overhead. rsync can also checks if the
> files transfered are the same or not. ftp does not
> From man rsync
> Note that rsync always verifies that each transferred file was
> correctly reconstructed on the receiving side by checking its
> whole-file checksum,...

I'd also take a look into 'unison', it is faster the rsync in
certain situation and its GUI might make things easier for
beginners, though you really want to use it from the shell to
take most advantages.

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo zvpunry@urvzvat.qr | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 6: global warming

On Sat, 03 May 2008 12:52:33 +0000, Goran Ivanic wrote:

> Assuem I want to transfer large amounts of stuff from one server to
> another (through Internet).
>
> Which method should I prefer:
>
> ftp or rsync ?
>
> What are the Pros and Cons?
>
> Which is faster?
>
> Which is more stable?
>
> Goran

http://stromberg.dnsalias.org/~strom...s-of-data.html

rsync is good at picking up where a prior transfer left off. rsync
defaults to ssh, but can use rsh or similar instead. ssh is too CPU-
intensive to get decent performance on gigabit or better networks even
with contemporary CPU's, but there are patches to openssh that take Some
of the performance hit out of it.

And as Robert said, ftp (and rsh and NFS) are not encrypted, so don't use
them to transfer anything you need to keep private (unless you combine
them with mcrypt or similar). These tools are fine for copying something
you'd be putting on a public web site anyway, for example (even without
mcrypt).

NFS is actually a pretty good performer on gigabit and better networks,
because it's able to make good use of jumbo frames. This despite NFS
giving lackluster performance on 10BaseT and 100BaseT. NFS reads are
quite a bit faster than NFS writes.

ssh (including with rsync), ftp, rsh (including with rsync) and NFS are
all pretty stable, though NFS is perhaps a little less so depending on
the implementations involved.

rsync gives OK progress information - not stellar. Modern ftp clients
like tnftp (formerly lukemftp) give good progress information. ssh and
rsh and NFS don't give progress info, but can give quite good progress
information if you combine them with a tool like http://
stromberg.dnsalias.org/~strombrg/reblock.html (there's a short list of
similar programs at the bottom of the page).

On Sat, 03 May 2008 12:52:33 +0000, Goran Ivanic wrote:

> Assuem I want to transfer large amounts of stuff from one server to
> another (through Internet).
>
> Which method should I prefer:
>
> ftp or rsync ?
>
> What are the Pros and Cons?
>
> Which is faster?
>
> Which is more stable?
>
> Goran

Here's a comparison of ssh, rsh, rsync, NFS, ftp and pnetcat for such a
purpose:

http://stromberg.dnsalias.org/~dstro...omparison.html

In comp.os.linux.misc Goran Ivanic <goran@lycos.com> wrote:
> Assume I want to transfer large amounts of stuff from one server to
> another (through Internet).

Either you do or you don't. It's hard enough understanding people's
questions without having unnecessary assumptions thrown about.


> Which method should I prefer:
> ftp or rsync ?

Your preference is entirely up to you. Personally, if it really was
"large amounts of stuff", I'd consider sending a tape through the post.


> What are the Pros and Cons?
> Which is faster?
> Which is more stable?

I think you probably ought to go and do your own homework, don't you?
Chris

Dan Stromberg <dstromberglists@gmail.com> writes:

>On Sat, 03 May 2008 12:52:33 +0000, Goran Ivanic wrote:

>> Assuem I want to transfer large amounts of stuff from one server to
>> another (through Internet).
>>
>> Which method should I prefer:
>>
>> ftp or rsync ?
>>
>> What are the Pros and Cons?
>>
>> Which is faster?
>>
>> Which is more stable?
>>
>> Goran

>Here's a comparison of ssh, rsh, rsync, NFS, ftp and pnetcat for such a
>purpose:

>http://stromberg.dnsalias.org/~dstro...omparison.html

Using rsync on ssh, the site
http://www.psc.edu/networking/projects/hpn-ssh/
shows taht it depends on far away the other machine is. If it is on the
same network where the roundtrip times are say 100usec, then even on Gb
links the standard ssh buffer is fast enough. If the machine to which you
are transfering stuff is much further away (many 10s-100s of msec) then ssh
acts as a bottleneck. But the code on that page claims to fix that problem.

So, for stability and for verification of the transfer, it is hard to beat
rsync. ftp, nfs,... do not verify that the data received is the same as the
data transfered. Of course you can put in an extra step to verify it.

Michael Heiming wrote:
> In comp.os.linux.networking Unruh <unruh-spam@physics.ubc.ca>:
>> Dave <foo@coo.com> writes:
>
>>> Goran Ivanic wrote:
>>>> Assuem I want to transfer large amounts of stuff from one server to another (through Internet).
>
>>>> Which method should I prefer:
>
>>>> ftp or rsync ?
> [..]
>
>>> My guess is ftp will be faster. It just moves the files, and does not
>>> care whether they exist on the other end or not.
>
>> On large files that is a trivial overhead. rsync can also checks if the
>> files transfered are the same or not. ftp does not
>> From man rsync
>> Note that rsync always verifies that each transferred file was
>> correctly reconstructed on the receiving side by checking its
>> whole-file checksum,...
>
> I'd also take a look into 'unison', it is faster the rsync in
> certain situation and its GUI might make things easier for
> beginners, though you really want to use it from the shell to
> take most advantages.
>
hey Michael,

what else unison can offer in particular what rsync cannot at this point
of time? What I understand is rsync is a one way transferr system
whereas unison can do multi-way sync of file transferrs across like
wansync/intellisync ... is that correct?