Spectrum Scale cluster configurations
IBM Spectrum Scale supports various cluster configurations that include SAN Shared Disk (SD), Network Shared Disk (NSD), and Shared Nothing (SN) clusters.
The cluster configurations SD and NSD were considered during this case study with the ECM WAS cluster.
While SD was the preferred cluster configuration for a system like the SUT, NSD was included into this case study too.
Note: The SD cluster configuration is the preferred model for smaller clusters (for example, less
than 50 servers) and provides the highest performance for cluster wide data access. The NSD
configuration provides access to a Spectrum File filesystem via a network connection by doing
network block I/O. Therefore, NSD clients do not need to be connected to the SAN. This enables
distant remote systems to mount shared filesystems including the high availability features provided
by Spectrum Scale.