Chapter 13 - Troubleshooting and Support
Network Setup Tips
Not Recommended:
• Single gigabit logical connection utilizing one of the 10GBase-T physical ports and a
Category 5e Ethernet cable
—OR—
• Single 10 gigabit logical connection utilizing one of the 10GBase-T physical ports and a
Category 6 Ethernet cable
Assign the appropriate IP address to the management and data ports either statically or
using DHCP. If you are setting the MTU to something other than 1500, ensure that your
switch configuration, as well as all the hosts on the network, support larger MTU settings.
The BlackPearl system can support jumbo frames (MTU=9000), but all switches and hosts on
the network must be configured to support jumbo frames if this is selected, or performance
might be degraded.
Link Aggregation Notes
Switches use different methods of routing traffic from hosts to NAS servers. There are also
many different network configurations to move data from hosts to NAS servers. For
example, some Cisco switches route traffic based on the MAC address and the IP address.
The BlackPearl system presents only one MAC address and one IP address when the data
ports are aggregated via DHCP; if static link aggregation is chosen, the BlackPearl system
presents only one MAC address, but can have up to 16 IP addresses aliased to the MAC
address. It is up to the switch to rotate data transfers among the physical ports on the
BlackPearl system in order to achieve the highest throughput possible.
Additionally, if link aggregation is configured for the BlackPearl system, then switches must
also be able to support link aggregation to aggregate or “trunk” the data ports together to
provide higher bandwidth into the system. Switches must support link aggregation using
LACP (Link Aggregation Control Protocol), and the switches must hash the destination IP
addresses. Manually configure LACP on the switch ports. LACP does not get enabled
automatically.
For example, if only a single host is connected to the BlackPearl system through a link
aggregated connection, the measured performance is lower than the potential maximum
transfer rate because only one physical port of the two port link aggregation is being
utilized by the switch. If a single share is mounted two times using different IP addresses
and transfers are started to that share from two separate hosts, the resulting throughput
would be approximately twice that of a single host connection. You may need to configure
more than two IP addresses on the BlackPearl system to force the switch hashing algorithm
to utilize all physical ports to maximize performance.
November 2020
User Guide-BlackPearl Converged Storage System
- 381 -
