10
Introduction
Figure 1-1.
Direct-Attached, Single-Cluster Configuration
EMC PowerPath Limitations in a Direct-Attached Cluster
EMC PowerPath provides failover capabilities and multiple path detection as
well as dynamic load balancing between multiple ports on the same storage
processor. However, direct-attached clusters supported by Dell connect to a
single port on each storage processor in the storage system. Because of the
single port limitation, PowerPath can provide only failover protection, not
load balancing, in a direct-attached configuration.
iSCSI SAN-Attached Cluster
In an iSCSI switch-attached cluster, all of the nodes are attached to a single
storage system or to multiple storage systems through redundant LANs for
high-availability. iSCSI SAN-attached clusters are superior to direct-attached
clusters in configuration flexibility, expandability, and performance.
Figure 1-2 shows an iSCSI SAN-attached cluster.
cluster node
private network
public network
cluster node
storage system
iSCSI connections
iSCSI connections
