Networking - Dell PowerVault NX3500 Technical Manual

Transition Guide for PowerVault MD3200i and MD3220i Series Arrays

12. Networking

iSCSI Connections
iSCSI connections provide the NX3500 controllers access to the storage
subsystem through Ethernet switches.
Internal Network
The PowerVault NX3500's internal network comprises two independent
1 GbE ports. The internal network is the infrastructure for PowerVault
NX3500 clustering, including the heartbeat monitor, transferring data,
mirroring information between the controllers' caches and distributing
data evenly across all LUNs in the system.
In a clustered solution, PowerVault NX3500 controllers are connected
peer-to-peer and employ dual links for redundancy and load balancing.
To achieve complete data distribution and to maintain high availability,
each of the controllers in the PowerVault NX3500 cluster system must
have access to the other controller in the system. The internal network
achieves this goal.
The PowerVault NX3500 internal management network (also known as
internal network B) connects both controllers. All internal
administrative related functions are performed on this network. In case
of a suspected "split brain" situation, in which the controllers in a
cluster lose communication with each other but continue to function
independently, the management network is used to automatically reset
the suspected controllers. This prevents a split brain situation while
ensuring data integrity.
Client Network
The connection between the PowerVault NX3500 solution and the NAS
client network is based on virtual IP addresses (VIP) that serve every
controller in the cluster. This enables clients to access the PowerVault
NX3500 as a single unit through the virtual IP network and enables the
system to load balance the network traffic between controllers, as well
as continue service if one controller fails. The client network comprises
two GbE NICs from each controller, which connect to client network
switches.
The PowerVault NX3500 supports multiple switch topologies. Working
with the Dell Services and support teams, you can select the ideal
topology for your environment. (Note: Best practices suggest that you
separate SAN and LAN traffic.)
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