XRootD Rados Open Storage System Plugin
=======================================

This project contains a plugin for the **XRootD** server which interfaces with
**librados** for the storage of data.

It is published under the GPLv3 license: http://www.gnu.org/licenses/gpl-3.0.html


Setup
======

This plugin is loaded by the XRootD Server. In order to accomplish this, it is
necessary to indicate the server where the plugin is by adding the following
line to the server's configuration file:

  ofs.osslib /path/to/libRadosOss.so

It is necessary to tell which Ceph cluster it should interface with. This is done
by adding the following file to the same configuration file indicated above:

  radososs.config /path/to/your/ceph.conf

The Rados Oss plugin maps pools with object names' prefixes. Thus, it is possible
to configure which prefixes point to which pools by setting the *radososs.pools*
variable in the configuration file similar to the following example:

  radososs.pools /test/:mytestpool:50 /:data

It is also possible to configure the maximum size allowed for the files written using
this plugin by adding :NUMBER after the pool's name as seen in the example above. The
size is in MB so the example above restricts files in *mytestpool* to have a maximum
size of 50 MB.

If you need the Rados instance to be created with a specific user name, you can do
it in the following way (myusername is an existing user name):

  radososs.user myusername

The default stripe size (RadosFS chunks files into sequential objects of <stripe size>)
is 128M. You can change the default size with:
  
  radososs.stripe 16777216

**IMPORTANT:** In order for the plugin to work correctly, it is also necessary to
disable *send file* and *async* in XRootD. This is done by adding the following
line to the configuration file:

  xrootd.async nosf off

The OSS supports the following CGI information in creation URLs:

    "?rfs.stripe=<bytes>"        - set the stripe size for this file to <bytes>