HOWTO: Access GRAND data on CCL multivolumes

The GRAND data stored on our system may be accessed through the Parrot tool. Users local to Notre Dame may make use of the cctools (including Parrot) straight out of AFS. A stable version of the cctools is always installed in /afs/nd.edu/user37/ccl/software/stable . Thus, to access Parrot, one may use the command 

% /afs/nd.edu/user37/ccl/software/stable/parrot_run
or set your shell to include the stable directory in its path.

Parrot executes a single command, given as its argument. To get many commands to execute in parrot, it is often useful to run parrot_run with the single command being a shell: 

% parrot_run tcsh

Parrot takes authentication arguments with the -a flag, some of which are globus credentials, ND Kerberos/AFS credentials, and hostname authentication. Other arguments to parrot_run can be researched in the documentation available on this site, or in its man page. Once inside parrot, local directories can be viewed, as well as other file servers using various protocols (FTP, HTTP, Chirp, etc.), which are accessed as though mounted under root.

For instance, to view the anonymous FTP server Chris has set up, from within Parrot: 

% cd /anonftp/grandpc.phys.nd.edu
or, to view Chris's webpage: 
% cat /http/www3.nd.edu/~cdandrea

More importantly for viewing your data, we will be using the "multivolume" framework, which is a prototype of the DSFS abstraction introduced here. Multivolumes are accessible in Parrot by /multi/host@name/. Your multivolumes are GRAND (for the original data) and SGRAND (for the shower data). Both are hosted on sc0-16.cse.nd.edu. These multivolumes are set up to be listable/readable by anyone logging in from the machines you generally have used (*.helios.nd.edu, *.phys.nd.edu, or *.hep.nd.edu), but not writable by those machines. We can change authentication and permissions as you require.

Thus, finally, to examine your data on our system, assuming you are on a physics linux box with parrot_run in your path: 

% parrot_run -a hostname tcsh[or your favorite shell]
% cd /multi/sc0-16.cse.nd.edu@GRAND
% ls

To examine the shower data on our system: 

% parrot_run -a hostname tcsh[or your favorite shell]
% cd /multi/sc0-16.cse.nd.edu@SGRAND
% ls
Standard Unix commands can be run on this directory from within parrot, including executables and shell scripts stored on your local machine, or in AFS space.

HOWTO: Manage GRAND Disk Changes

  1. Delete current FTP links
  2. Unmount old disk from main
  3. Mount new disk as main
  4. Restart data acquisition
  5. Remount old disk as alternate
  6. Check CCL system for unacquired files
  7. Create new FTP links to those files (or copy from old onto new)
  8. Eventually, verify CCL system versus old before moving old completely offline

If you have any questions, or find there is an error in this how-to, please let me know.


--Christopher Moretti [an error occurred while processing this directive]