If you are using Myri-10G “8C” adapters (10G-PCIE2-8C2-2S or 10G-PCIE2-8C2- 2S-SYNC) with SFP+-terminated copper “direct attach” cables and you experience link up/down connectivity issues or bad crc errors, try loading the myri_snf driver with the load-time option myri_serdes_mode=2.
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Note: The myri_serdes_mode load-time option is available in Sniffer10G 2.0.12.50399 and later.
On Linux, issue the following command:
# /opt/snf/sbin/myri_start_stop start myri_serdes_mode=2
On Windows, the equivalent instructions are:
Create the following registry key (followed by a reboot):
REG ADD HKLM\SYSTEM\CurrentControlSet\services\snf /v myri_serdes_mode /t REG_DWORD /d 2
We have documented cases where certain direct attach cables work better with 10G-PCIE2-8C2-2S-SYNC adapters when SFP+ settings for the serdes chip on the adapter are used instead of direct attach settings.
All of the possible options to myri_serdes_mode=X are as follows:
0: Autodetect (default) 1: Force use of direct attach cable settings. 2: Force use of SFP+ 10GBase-SR/10GBase-LR settings. 3: Force use of SFP+ 10GBase-LRM settings. All other values are reserved for future use.
If you are using Myri-10G “8B” adapters (e.g., 10G-PCIE2-8B2-2S), the load-time option myri_serdes_mode=X will be ignored. If you experience link up/down connectivity issues or bad crcs errors with the Myri-10G “8B” adapters and direct attach cables, please try a shorter length direct attach cable or replace the direct attach cable with an SFP+ transceiver module and fiber cable.
