How to use gridftp

In general the remote site should be running a gsiftp server which will accept your user credentials (X.509 grid certificate).

The full syntax is of globus-url-copy is

globus-url-copy [-help | -usage] [-version[s]] [-vb] [-dbg] [-b | -a]
                        [-q] [-r] [-rst] [-f <filename>]
                        [-s <subject>] [-ds <subject>] [-ss <subject>]
                        [-tcp-bs <size>] [-bs <size>] [-p <parallelism>]
                        [-notpt] [-nodcau] [-dcsafe | -dcpriv]
                        <sourceURL> <destURL>

However, most of the time you can get away with only a few of these options:

Use Case: Transfer a file from UWM to Atlas

Imagine I have a file sitting at UWM called random in my home /home/caulbert and want to push it to Atlas:

globus-url-copy -tcp-bs 1048576 -vb -p 16 file:/home/caulbert/random gsiftp://carsten@atlas.atlas.aei.uni-hannover.de/home/carsten/

Trying that this will output something along these lines:

Source: file:/home/caulbert/
Dest:   gsiftp://carsten@atlas.atlas.aei.uni-hannover.de/home/carsten/
  random
   1048576000 bytes        34.13 MB/sec avg         3.20 MB/sec inst

Please note the following:

• you may need to provide the remote user name in the gsiftp URL, most likely because your certificate is mapped to more than one user
• the settings for tcp-bs (TCP buffer size) and p (parallelism) can be tuned for more throughput, but be aware that you might consume valuable resources from other users, especially for long-distance connections (or more precisely links with a large round trip time RTT) might need large TCP buffer sizes
• the option r enables you to recursively copy a directure (structure), however, please note that many small files are extremely sub-optimal for this tool
• as a final word of warning, this tool works best with large files (many 100 MB or GB), so please consider using tar initially if possible to reduce the transfer times later on

-- CarstenAulbert - 28 Jan 2009