Overview

SFTP is and SCP are a secure file transfer protocol based on SSH. One should notice that it's a single-stream protocol. It can also be significantly slower than others due to its internal data encription. The protocol doesn't seem to be optimized for transferring data over WAN. Our preliminary tests (in a specific setup between SLAC and IN2P3/France) indicate that the maximum transfer rate would be less than 0.5 MBytes/sec. This is nearly 3 times less than it can be achieved with specialized tools like BBCP or FDT.

ATTENTION:

Using

Here is an example of a sample session:

...

protocols sending data over encrypted SSH transport. In general these tools are significantly slower compared to bbcp and Globus because all data are encrypted and are transferred over a single stream between the SLAC and the remote host. The transfer optimized tools bbcp and Globus typically don't encrypt the data and employ multiple streams to increase the transfer rate.

The main advantage of SFTP (or scp) is their easy of use compared to the other tools and that they are usually installed on any Linux/Unix computer. Both SFTP and SCP are based on SSH and will show the same performance.

Usage examples

Here is a basic example of an interactive session (a password for SLAC UNIX user 'user' is being requested):

% sftp user@psexport.slac.stanford.edu:/reg/d/psdm/mfx/mfx12345/scratch/MyDataFile.dat ./
Connecting to psexport01.slac.stanford.edu...
user@psexport01.slac.stanford.edu's password:
Fetching /usr/work/user/MyDataFile.dat to ./MyDataFile.dat
...

For scp the similar command line would be used:
% scp user@psexport.slac.stanford.edu:/reg/d/psdm/mfx/mfx12345/scratch/MyDataFile.dat ./

The command can also be used in the batch mode. See UNIX man pages for further detail.