** THIS PAGE IS A WORK IN PROGRESS **

Accessing grid storage

Grid storage facilities can be accessed through from any node in the Shark resource cluster. Allowed protocols include SRM, GridFTP and HTTPS/WebDAV.

With all things grid, make sure you have a valid grid certificate and are a member of the required VOs. For more information see the SURFSARA grid wiki.

Installing your grid certificate

A grid certificate uniquely identifies you to grid compute and storage facilities. Please install your certificate on Shark using the instructions outlined on the relevant SURFSARA page. Following these instructions will result in a .globus directory in your home directory, containing a userkey.pem and usercert.pem.

Creating a certificate proxy

In order to access grid storage, you will need to create a certificate proxy from your actual certificate. A proxy allows you to use the grid for a limited amount of time (typically a week), after which it expires. To create a proxy, use voms-proxy-init as follows:

voms-proxy-init -vomses /etc/vomses -voms lsgrid -out grid-proxy      

This will create a certificate proxy in the file grid-proxy.

Example:

# mhmoed at shark in ~ [11:42:29]
$ voms-proxy-init -vomses /etc/vomses -voms lsgrid -out grid-proxy      
Enter GRID pass phrase:
Your identity: /DC=org/DC=terena/DC=tcs/C=NL/O=Leids Universitair Medisch Centrum/CN=Matthijs Herman Moed 94399-lumcnet@lumc.nl
Creating temporary proxy ........................................ Done
Contacting  voms.grid.sara.nl:30018 [/O=dutchgrid/O=hosts/OU=sara.nl/CN=voms.grid.sara.nl] "lsgrid" Done
Creating proxy .......................................................... Done

Your proxy is valid until Wed Oct 29 23:42:58 2014 }}}

Each storage operation (copying, removing, listing directory contents, etc.) requires you to identify yourself with this proxy. Although this can be done manually for each command, it is easier to create an environment variable for this. In order to create this environment variable, please use the following command:

export X509_USER_PROXY=$PWD/grid-proxy

Transferring data

There are various ways of copying data from, to and across the grid.

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