The Extended root file server consists of a file server called xrootd
and a cluster management server called cmsd.

The xrootd server was developed for the root analysis framework to
serve root files. However, the server is agnostic to file types and
provides POSIX-like access to any type of file.

The cmsd server is the next generation version of the olbd server,
originally developed to cluster and load balance Objectivity/DB AMS
database servers. It provides enhanced capability along with lower
latency and increased throughput.