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Dell Storage for HPC with Intel Enterprise Edition for Lustre sofware
manages one or more OSTs. Typically, there are several active OSSs at any time. Lustre is able to
deliver increased throughput by increasing the number of active OSSs (and associated OSTs). Each
additional OSS increases the existing networking throughput, while each additional OST increases the
storage capacity. Figure 1 shows the relationship of the MDS, MDT, MGS, OSS and OST components of a
typical Lustre configuration. Clients in the figure are the HPC cluster’s compute nodes.
Figure 1: Lustre based storage solution components
A parallel file system, such as Lustre, delivers performance and scalability by distributing data
(“striping” data) across multiple Object Storage Targets (OSTs), allowing multiple compute nodes to
efficiently access the data simultaneously. A key design consideration of Lustre is the separation of
metadata access from IO data access in order to improve the overall system performance.
The Lustre client software is installed on the compute nodes to allow access to data stored on the
Lustre file system. To the clients, the file system appears as a single namespace that can be mounted
for access. This single mount point provides a simple starting point for application data access, and
allows access via native client operating system tools for easier administration.
Lustre includes a sophisticated and enhanced storage network protocol, Lustre Network, referred to as
LNet. LNet is capable of leveraging certain types of network features. For example, when the Dell
Storage for HPC with Intel EE for Lustre utilizes InfiniBand as the network to connect the clients, MDSs
and OSSs, LNet enables Lustre to take advantage of the RDMA capabilities of the InfiniBand fabric to
provide faster I/O transport and lower latency than experienced with typical networking protocols.
To summarize, the elements of the Lustre file system are as follows:
 Metadata Target (MDT) – Stores the location of “stripes” of data, file names, time stamps, etc.
 Management Target (MGT) – Stores management data such as configuration and registry
 Metadata Storage Server (MDS) – Manages the MDT, providing Lustre clients access to files.
 Object Storage Target (OST) – Stores the data stripes or extents of the files on a file system.
 Object Storage Server (OSS) – Manages the OSTs, providing Lustre clients access to the data.