Data objects are stored in iRODS on storage resources. A storage resources can be a directory in file system, tape system or a network resource (e.g., Amazon S3 or FTP). Standard iRODS installation create a default resource (so called Vault), but it is possible to add further resources for instance to account for increasing user requirements. This is done by using admin tool iadmin and a command to add new storage resource looks like:

iadmin mkresc Name Type Class Host [Path]

Each resource must have a unique name, type and resource class. It can be located on any iRODS server within one zone (unambiguously identified by the tuple hostname and path). Available resource types can be determined with iadmin lt resc_type, currently the list comprises of:

  • unix file system
  • HPSS file system
  • windows file system
  • S3
  • MSS universal driver
  • database
  • mso

Two main resources classes are:

  • Cache (short access times e.g., file systems)
  • Archival (longer access times e.g., tape systems)

It is also possible to use file system directory as archival type (the default iRODS resource created during the installation is an archive in directory). The list of all possible resource classes iadmin lt resc_class. An example command to add new resource is:

iadmin mkresc newResource 'unix file system' archive localhost.localdomain /path/to/some/dir/

To test whether the resource works properly, one can replicate some data to it (for instance an existing collection /tempZone/home/rods/toRep):

irepl -r -R newResource -V /tempZone/home/rods/toRep ils -L /tempZone/home/rods/toRep

The ils command should show that the content of the collection is now stored on two resources. Expected output for two resourced based on unix file system would be:

/tempZone/home/rods/toRep: rods 0 defaultResource 102400 2012-08-17.10:20 & file.dat /path/to/defaultResource/home/rods/toRep/file.dat rods 1 newResource 102400 2012-08-17.10:58 & file.dat /path/to/newResource/home/rods/toRep/file.dat

To simplify the management of resources it is possible to group two or more physical resources into a resource group.