5
Thunderbolt device. Figure 1 shows the shared ports of the Apple Mac Pro. Note that bus 0 shares a port with the Mac Pro HDMI
connection. The 2 lower ports on Bus 0 should be avoided if a display is connected to the Mac Pro via the built-in HDMI interface.
Figure 1. Thunderbolt 2 Bus Configuration of Apple Mac Pro
Mac OS X Performance Tuning
Ensure that your clients are running current OS patch levels and the latest version of the ATTO Technology 10 GbE drivers.
For optimal 10 GbE performance, the following entries are added to the file /etc/sysctl.conf on clients running Linux or Mac OS 10.9
and greater.
net.inet.tcp.sendspace=1048576
net.inet.tcp.recvspace=1048576
net.inet.tcp.delayed_ack=3
net.inet.tcp.rfc1323=1
The
net.inet.tcp.sendspace
and
net.inet.tcp.recvspace
system control values determine the client OS transmit and receive
buffer sizes. The minimum recommended transmit and receive buffer sizes for a client’s network connectivity to EMC Isilon scale-out
NAS may be determined using the following equation.
Network bandwidth (bytes per second) x round-trip delay (seconds) = buffer size (bytes)
The
net.inet.tcp.delayed_ack
system control determines when TCP delayed acknowledgment is enabled. 0 will disable the
feature and responds to every packet. A setting of 1 implies that an ack will be sent for every 6 packets. A setting of 2 implies an
ack after every 2 packets (compatibility mode) which may be desirable in certain network topologies. The setting of 3, automatically
determine when to employ a delayed ack, is recommended in most cases.
The
net.inet.tcp. rfc1323
system control should be set to 1 to enable window scaling
Jumbo frames support for the ATTO Technology 10 GbE network adapter is enabled via the Mac OS X network preferences pane.
Please see the “Network design considerations”
For more information on Mac OS X network performance tuning, please see the EMC Isilon document
