- MDTs are supported. Each file system has at least one MDT. An MDT on
- a shared storage target can be available via multiple MDSs, although
- only one MDS can export the MDT to the clients at one time. Two MDS
- machines share storage for two or more MDTs. After the failure of one
- MDS, the remaining MDS begins serving the MDT(s) of the failed
- MDS.</para>
+ MDTs are supported in the Distributed Namespace Environment (DNE).
+ In addition to the primary MDT that holds the filesystem root, it
+ is possible to add additional MDS nodes, each with their own MDTs,
+ to hold sub-directory trees of the filesystem.</para>
+ <para condition="l28">Since Lustre software release 2.8, DNE also
+ allows the filesystem to distribute files of a single directory over
+ multiple MDT nodes. A directory which is distributed across multiple
+ MDTs is known as a <emphasis>striped directory</emphasis>.</para>