Napatech Setup¶

In order to have n2disk working with the highest performances on Napatech adapters, the system need to be properly configured. Once the Napatech software has been installed, you should customise the /opt/napatech3/config/ntservice.ini configuration file modifying the parameters as below.

Standard PCAP with microsecond timestamps:

TimestampFormat = PCAP

PCAP with nanosecond timestamps:

TimestampFormat = PCAP_NS

Packet descriptor:

PacketDescriptor = PCAP

Segment size (maximum 4MB):

HostBufferSegmentSizeRx = 4

Optionally, increase RX host buffer to 128 MB:

HostBuffersRx = [4,128,0]

Once customisation has been completed, the Napatech driver can be started with:

/opt/napatech3/bin/ntstart.sh

The PF_RING driver can be loaded using the specific pf_ring startup script:

/etc/init.d/pf_ring start

or using systemctl:

systemctl start pf_ring

Now you are ready to start n2disk:

n2disk -o /storage -p 1000 -b 4000 -i nt:0 -q 1 -C 1024 -c 1 -z 2 -w 3 -n 50 -m 100

where nt:0 means Napatech port 0.

The Napatech card can be instructed to create a stream, for instance aggregating two ports. It is possible to open a stream using nt:stream<ID> as interface name. Example:

ntpl -e "Assign[streamid=0] = port == 0,1"

n2disk -o /storage -p 1000 -b 4000 -i nt:stream0 -q 1 -C 1024 -w 0 -c 1 --disk-limit 80%