Release Notes

PS Series SAN design
36 Dell PS Series Configuration Guide
- FS7610 NAS Appliance: 8x10GbE Ethernet ports per appliance = 4 x 10GbE SFP+ Ethernet
ports per NAS controller for client connectivity and 4 x 10GbE SFP+ Ethernet ports per NAS
controller for SAN connectivity
• At least two iSCSI SAN ports per host (block level iSCSI access) are required for fully redundant SAN
connectivity. Host ports can be 1GbE or 10GbE and the host speed should match the array port
speed.
• Quality of Service (QoS) based on what is traditionally designated as IEEE 802.1p is not currently
supported for use with PS Series SANs. QoS and Class of Service designations must be disabled.
• All switches within the SAN must be interconnected such that there is always a path from any
Ethernet port on one array to all other Ethernet ports on all other arrays in the group.
• All switches and host network controllers within the infrastructure must have (at a minimum, receive)
flow control enabled for optimal performance.
• Any PS Series SAN group that is required to send or receive replication traffic to/from another SAN
group must have an uninterrupted communications path (visibility) between each group.
• To prevent a switch failure from also disabling all paths between a host and its connected volumes,
all ports from each controller need to be connected to at least two different physical switches. This
also applies to LAN side connections in FS Series NAS appliance configurations. (Refer to the
connection diagrams in Section 12.1)
• For PS4100/PS6100 family arrays, split the vertical port pair connections between two switches to
ensure 100% bandwidth capability is maintained in the event of a vertical port failover event.
• Do not block IPv6 discovery traffic on the SAN internal switches when utilizing FS Appliances
FS76x0 uses IPv6 discovery for internal communication and setup only; not for user data. Client
communication occurs over IPv4
• For SANs connecting to an FS Series appliance, all switches in the SAN must have jumbo frames
enabled.
• Take advantage of your switch’s VLAN capabilities. You may optionally create a VLAN dedicated to
iSCSI traffic (even on dedicated switches). If necessary, create a second VLAN for management
traffic. The actual VLAN configuration of your iSCSI SAN will be dictated by your SAN network design
requirements and the features of the iSCSI SAN switches being used.
• Jumbo frames should be enabled for best performance. If you choose to use jumbo frames then all
nodes in the SAN fabric must have Jumbo frames enabled.
• For best performance and reliability, we recommend that all interconnection paths between non-
stacking switches (LAGs) use a dynamic link aggregation protocol such as LACP
8.1.3 Quality of service (QoS)
QoS is described as either of the following:
• The ability to provide different priority levels to different applications, users, or data flows, or to
guarantee a certain level of performance to a data flow.
• A network function implemented in some routers and switches that provides high priority for certain
types of latency-sensitive traffic (for example, VoIP) and lower priority for other types of traffic (for
example, web or http).
PS Series arrays are designed to provide I/O as fast as your network can support it. Therefore, using QoS
with iSCSI traffic does not produce expected or desirable results on the SAN. Also, QoS rules can affect how
well–or even whether–replication succeeds between PS Series groups. If you plan to use QoS, Dell EMC
recommends that you use it only on Wide Area Network (WAN) connections, where bandwidth is shared with
other applications and the PS Series array uses it for time-insensitive replication traffic.