Logical storage units in VOSpace 1.1

From: Matthew Graham <mjg-at-cacr.caltech.edu>
Date: Mon, 13 Aug 2007 11:32:08 -0700


Hi,

A request has from our friends at SDSC to include references to the actual storage units that data is being deposited on. The use case is data replication so, for example, I want to move/copy a data object from a slow tape archive to an ultrafast disk but both hardware units are within the same VOSpace or I want to retrieve a data object from the ultrafast disk copy and not the slow tape one.

I think that we can incorporate this easily into our existing data model. We will refer to hardware units as logical storage units with the implication that they are identified via a logical identifier (URI) that is set by the particular VOSpace implementation. To get the list of available storage units from a VOSpace, we will need a method: getLogicalStorageUnits() which will return a list of URIs. These URIs may be resolvable to a description of the storage unit.

The logical storage unit identifier will be an optional argument in the <transfer> entity so that as part of the data transfer negotiation, the user can specify a list of storage units that they want the data transferred to/from. The identifier will also be an optional argument in the <node> entity so that specific hardware can be targetted in moving and copying data.

Comments, suggestions, etc.

    Cheers,

    Matthew Received on 2007-08-13Z20:33:23